[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_ship_from_store
Scenario ID: retail_f8_ship_from_store_v4

[BUSINESS DESCRIPTION]
Business narrative:
Stores fulfill both walk-in traffic and online orders, effectively acting as small fulfillment centers that ship from store. Storage capacity and labor capacity at stores are scaled up, but labor usage per unit is higher when stores serve both channels. Demand from walk-in and online customers is aggregated into a single local demand stream per product and location, and unmet demand is lost and penalized.

Structure cues:
- The inventory structure is single-echelon with local demand at each location, storage capacity, and lost sales.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. Storage capacities are scaled to 5x normal values to accommodate dual-channel operations.
- Labor capacity: The JSON provides labor_cap=500 per location per period, with higher labor_usage per product (SKU_Basic=0.5, SKU_Premium=0.8, SKU_ShortLife=0.6) reflecting the additional work from online fulfillment.
- Stores conceptually serve two demand streams, but the model treats them as a single aggregated demand per product and location.
- Inventory remains non-negative and is updated from previous stock and production, minus sales and waste.
- There is no transshipment; lead times are zero, and substitution behavior remains as encoded.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) while balancing higher labor intensity against increased capacity.

[DATA SCHEMA]
{
  "name": str,                          # scenario identifier
  "periods": int,                       # number of time periods
  "products": [str, ...],               # list of product IDs
  "locations": [str, ...],              # list of location IDs

  "shelf_life": {p: int},               # shelf life in periods per product
  "lead_time": {p: int},                # order lead time per product (0 = same-period arrival)

  "demand_curve": {p: [float, ...]},    # demand per product per period (0-indexed list)
  "demand_share": {l: float},           # fraction of total demand at each location

  "production_cap": {p: [float, ...]},  # max production per product per period (0-indexed list)
  "cold_capacity": {l: float},          # storage capacity per location
  "cold_usage": {p: float},             # storage units per unit of product

  "labor_cap": {l: [float, ...]},       # labor hours per location per period (0-indexed list)
  "labor_usage": {p: float},            # labor hours per unit sold
  "return_rate": {p: float},            # fraction of sales returned next period

  "costs": {
    "purchasing": {p: float},           # cost per unit ordered
    "inventory": {p: float},            # holding cost per unit per period
    "waste": {p: float},                # cost per unit expired
    "lost_sales": {p: float},           # penalty per unit of unmet demand
    "fixed_order": float,               # fixed cost per order placed
    "transshipment": float              # cost per unit transshipped
  },

  "constraints": {
    "moq": float,                       # minimum order quantity (0 = no MOQ)
    "pack_size": int,                   # order must be multiple of this (1 = no constraint)
    "budget_per_period": float|null,    # max purchasing cost per period
    "waste_limit_pct": float|null       # max waste as fraction of total demand
  },

  "network": {
    "sub_edges": [[p_from, p_to], ...], # substitution: p_from's demand can be served by p_to
    "trans_edges": [[l_from, l_to], ...]# transshipment: can ship from l_from to l_to
  }
}

[DATA ACCESS]
- The variable `data` is pre-loaded. Do NOT use file I/O.
- Lists are 0-indexed (period t in model uses index [t-1] in data arrays)

CRITICAL - Network edges require tuple conversion for Gurobi:
  sub_edges = [tuple(e) for e in data.get('network', {}).get('sub_edges', [])]
  trans_edges = [tuple(e) for e in data.get('network', {}).get('trans_edges', [])]

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that models and solves this optimization problem.

[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_ship_from_store
Scenario ID: retail_f8_ship_from_store_v4

[BUSINESS DESCRIPTION]
Business narrative:
Stores fulfill both walk-in traffic and online orders, effectively acting as small fulfillment centers that ship from store. Storage capacity and labor capacity at stores are scaled up, but labor usage per unit is higher when stores serve both channels. Demand from walk-in and online customers is aggregated into a single local demand stream per product and location, and unmet demand is lost and penalized.

Structure cues:
- The inventory structure is single-echelon with local demand at each location, storage capacity, and lost sales.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. Storage capacities are scaled to 5x normal values to accommodate dual-channel operations.
- Labor capacity: The JSON provides labor_cap=500 per location per period, with higher labor_usage per product (SKU_Basic=0.5, SKU_Premium=0.8, SKU_ShortLife=0.6) reflecting the additional work from online fulfillment.
- Stores conceptually serve two demand streams, but the model treats them as a single aggregated demand per product and location.
- Inventory remains non-negative and is updated from previous stock and production, minus sales and waste.
- There is no transshipment; lead times are zero, and substitution behavior remains as encoded.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) while balancing higher labor intensity against increased capacity.

[DATA]
The following JSON contains all instance data. Parse it directly in your code.

```json
{
  "name": "retail_f8_ship_from_store_v4",
  "description": "Standard seasonal retail scenario.",
  "periods": 20,
  "products": [
    "SKU_Basic",
    "SKU_Premium",
    "SKU_ShortLife"
  ],
  "locations": [
    "DC1",
    "DC2",
    "DC3",
    "DC4",
    "DC5"
  ],
  "shelf_life": {
    "SKU_Basic": 10,
    "SKU_Premium": 8,
    "SKU_ShortLife": 4
  },
  "lead_time": {
    "SKU_Basic": 0,
    "SKU_Premium": 0,
    "SKU_ShortLife": 0
  },
  "cold_capacity": {
    "DC1": 22599.64979107614,
    "DC2": 19828.71384348629,
    "DC3": 14887.23413797763,
    "DC4": 13800.155656911498,
    "DC5": 14039.23739623958
  },
  "cold_usage": {
    "SKU_Basic": 1.0,
    "SKU_Premium": 3.0,
    "SKU_ShortLife": 1.2
  },
  "production_cap": {
    "SKU_Basic": [
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800
    ],
    "SKU_Premium": [
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400
    ],
    "SKU_ShortLife": [
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500
    ]
  },
  "labor_cap": {
    "DC1": [
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0
    ],
    "DC2": [
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0
    ],
    "DC3": [
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0
    ],
    "DC4": [
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0
    ],
    "DC5": [
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0,
      500.0
    ]
  },
  "labor_usage": {
    "SKU_Basic": 0.5,
    "SKU_Premium": 0.8,
    "SKU_ShortLife": 0.6
  },
  "return_rate": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "demand_curve": {
    "SKU_Basic": [
      309,
      321,
      368,
      323,
      499,
      508,
      700,
      844,
      970,
      1126,
      1482,
      1189,
      1145,
      811,
      639,
      533,
      469,
      404,
      320,
      266
    ],
    "SKU_Premium": [
      148,
      141,
      180,
      165,
      190,
      287,
      349,
      405,
      495,
      582,
      584,
      550,
      628,
      478,
      394,
      307,
      248,
      193,
      149,
      136
    ],
    "SKU_ShortLife": [
      127,
      121,
      145,
      131,
      185,
      250,
      321,
      399,
      445,
      500,
      587,
      540,
      458,
      325,
      309,
      186,
      149,
      137,
      120,
      123
    ]
  },
  "demand_share": {
    "DC1": 0.25,
    "DC2": 0.2,
    "DC3": 0.2,
    "DC4": 0.2,
    "DC5": 0.15
  },
  "costs": {
    "lost_sales": {
      "SKU_Basic": 50.0,
      "SKU_Premium": 80.0,
      "SKU_ShortLife": 40.0
    },
    "inventory": {
      "SKU_Basic": 1.0,
      "SKU_Premium": 1.5,
      "SKU_ShortLife": 1.0
    },
    "waste": {
      "SKU_Basic": 2.0,
      "SKU_Premium": 3.0,
      "SKU_ShortLife": 2.0
    },
    "fixed_order": 0.0,
    "transshipment": 0.5,
    "purchasing": {
      "SKU_Basic": 10.0,
      "SKU_Premium": 20.0,
      "SKU_ShortLife": 15.0
    }
  },
  "constraints": {
    "moq": 0,
    "pack_size": 1,
    "budget_per_period": null,
    "waste_limit_pct": null
  },
  "network": {
    "sub_edges": [
      [
        "SKU_Basic",
        "SKU_Premium"
      ]
    ],
    "trans_edges": []
  }
}
```

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB; import json
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that:
1. Parses the JSON data above (use json.loads on the string)
2. Models and solves the optimization problem
3. Prints status and objective value

Standard seasonal retail scenario.


[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v0

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA SCHEMA]
{
  "name": str,                          # scenario identifier
  "periods": int,                       # number of time periods
  "products": [str, ...],               # list of product IDs
  "locations": [str, ...],              # list of location IDs

  "shelf_life": {p: int},               # shelf life in periods per product
  "lead_time": {p: int},                # order lead time per product (0 = same-period arrival)

  "demand_curve": {p: [float, ...]},    # demand per product per period (0-indexed list)
  "demand_share": {l: float},           # fraction of total demand at each location

  "production_cap": {p: [float, ...]},  # max production per product per period (0-indexed list)
  "cold_capacity": {l: float},          # storage capacity per location
  "cold_usage": {p: float},             # storage units per unit of product

  "labor_cap": {l: [float, ...]},       # labor hours per location per period (0-indexed list)
  "labor_usage": {p: float},            # labor hours per unit sold
  "return_rate": {p: float},            # fraction of sales returned next period

  "costs": {
    "purchasing": {p: float},           # cost per unit ordered
    "inventory": {p: float},            # holding cost per unit per period
    "waste": {p: float},                # cost per unit expired
    "lost_sales": {p: float},           # penalty per unit of unmet demand
    "fixed_order": float,               # fixed cost per order placed
    "transshipment": float              # cost per unit transshipped
  },

  "constraints": {
    "moq": float,                       # minimum order quantity (0 = no MOQ)
    "pack_size": int,                   # order must be multiple of this (1 = no constraint)
    "budget_per_period": float|null,    # max purchasing cost per period
    "waste_limit_pct": float|null       # max waste as fraction of total demand
  },

  "network": {
    "sub_edges": [[p_from, p_to], ...], # substitution: p_from's demand can be served by p_to
    "trans_edges": [[l_from, l_to], ...]# transshipment: can ship from l_from to l_to
  }
}

[DATA ACCESS]
- The variable `data` is pre-loaded. Do NOT use file I/O.
- Lists are 0-indexed (period t in model uses index [t-1] in data arrays)

CRITICAL - Network edges require tuple conversion for Gurobi:
  sub_edges = [tuple(e) for e in data.get('network', {}).get('sub_edges', [])]
  trans_edges = [tuple(e) for e in data.get('network', {}).get('trans_edges', [])]

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that models and solves this optimization problem.

[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v0

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA]
The following JSON contains all instance data. Parse it directly in your code.

```json
{
  "name": "retail_f8_sustainability_v0",
  "description": "Standard seasonal retail scenario.",
  "periods": 20,
  "products": [
    "SKU_Basic",
    "SKU_Premium",
    "SKU_ShortLife"
  ],
  "locations": [
    "DC1",
    "DC2",
    "DC3",
    "DC4",
    "DC5"
  ],
  "shelf_life": {
    "SKU_Basic": 10,
    "SKU_Premium": 8,
    "SKU_ShortLife": 4
  },
  "lead_time": {
    "SKU_Basic": 0,
    "SKU_Premium": 0,
    "SKU_ShortLife": 0
  },
  "cold_capacity": {
    "DC1": 4000,
    "DC2": 3500,
    "DC3": 3000,
    "DC4": 3000,
    "DC5": 2500
  },
  "cold_usage": {
    "SKU_Basic": 1.0,
    "SKU_Premium": 3.0,
    "SKU_ShortLife": 1.2
  },
  "production_cap": {
    "SKU_Basic": [
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800
    ],
    "SKU_Premium": [
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400
    ],
    "SKU_ShortLife": [
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500
    ]
  },
  "labor_cap": {
    "DC1": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC2": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC3": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC4": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC5": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ]
  },
  "labor_usage": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "return_rate": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "demand_curve": {
    "SKU_Basic": [
      303,
      311,
      328,
      365,
      435,
      549,
      711,
      906,
      1100,
      1245,
      1300,
      1245,
      1100,
      906,
      711,
      549,
      435,
      365,
      328,
      311
    ],
    "SKU_Premium": [
      151,
      155,
      164,
      182,
      217,
      274,
      355,
      453,
      550,
      622,
      650,
      622,
      550,
      453,
      355,
      274,
      217,
      182,
      164,
      155
    ],
    "SKU_ShortLife": [
      121,
      124,
      131,
      146,
      174,
      219,
      284,
      362,
      440,
      498,
      520,
      498,
      440,
      362,
      284,
      219,
      174,
      146,
      131,
      124
    ]
  },
  "demand_share": {
    "DC1": 0.25,
    "DC2": 0.2,
    "DC3": 0.2,
    "DC4": 0.2,
    "DC5": 0.15
  },
  "costs": {
    "lost_sales": {
      "SKU_Basic": 50.0,
      "SKU_Premium": 80.0,
      "SKU_ShortLife": 40.0
    },
    "inventory": {
      "SKU_Basic": 1.0,
      "SKU_Premium": 1.5,
      "SKU_ShortLife": 1.0
    },
    "waste": {
      "SKU_Basic": 2.0,
      "SKU_Premium": 3.0,
      "SKU_ShortLife": 2.0
    },
    "fixed_order": 0.0,
    "transshipment": 0.5,
    "purchasing": {
      "SKU_Basic": 10.0,
      "SKU_Premium": 20.0,
      "SKU_ShortLife": 15.0
    }
  },
  "constraints": {
    "moq": 0,
    "pack_size": 1,
    "budget_per_period": null,
    "waste_limit_pct": 0.02
  },
  "network": {
    "sub_edges": [
      [
        "SKU_Basic",
        "SKU_Premium"
      ]
    ],
    "trans_edges": []
  }
}
```

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB; import json
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that:
1. Parses the JSON data above (use json.loads on the string)
2. Models and solves the optimization problem
3. Prints status and objective value

Standard seasonal retail scenario.


[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v1

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA SCHEMA]
{
  "name": str,                          # scenario identifier
  "periods": int,                       # number of time periods
  "products": [str, ...],               # list of product IDs
  "locations": [str, ...],              # list of location IDs

  "shelf_life": {p: int},               # shelf life in periods per product
  "lead_time": {p: int},                # order lead time per product (0 = same-period arrival)

  "demand_curve": {p: [float, ...]},    # demand per product per period (0-indexed list)
  "demand_share": {l: float},           # fraction of total demand at each location

  "production_cap": {p: [float, ...]},  # max production per product per period (0-indexed list)
  "cold_capacity": {l: float},          # storage capacity per location
  "cold_usage": {p: float},             # storage units per unit of product

  "labor_cap": {l: [float, ...]},       # labor hours per location per period (0-indexed list)
  "labor_usage": {p: float},            # labor hours per unit sold
  "return_rate": {p: float},            # fraction of sales returned next period

  "costs": {
    "purchasing": {p: float},           # cost per unit ordered
    "inventory": {p: float},            # holding cost per unit per period
    "waste": {p: float},                # cost per unit expired
    "lost_sales": {p: float},           # penalty per unit of unmet demand
    "fixed_order": float,               # fixed cost per order placed
    "transshipment": float              # cost per unit transshipped
  },

  "constraints": {
    "moq": float,                       # minimum order quantity (0 = no MOQ)
    "pack_size": int,                   # order must be multiple of this (1 = no constraint)
    "budget_per_period": float|null,    # max purchasing cost per period
    "waste_limit_pct": float|null       # max waste as fraction of total demand
  },

  "network": {
    "sub_edges": [[p_from, p_to], ...], # substitution: p_from's demand can be served by p_to
    "trans_edges": [[l_from, l_to], ...]# transshipment: can ship from l_from to l_to
  }
}

[DATA ACCESS]
- The variable `data` is pre-loaded. Do NOT use file I/O.
- Lists are 0-indexed (period t in model uses index [t-1] in data arrays)

CRITICAL - Network edges require tuple conversion for Gurobi:
  sub_edges = [tuple(e) for e in data.get('network', {}).get('sub_edges', [])]
  trans_edges = [tuple(e) for e in data.get('network', {}).get('trans_edges', [])]

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that models and solves this optimization problem.

[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v1

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA]
The following JSON contains all instance data. Parse it directly in your code.

```json
{
  "name": "retail_f8_sustainability_v1",
  "description": "Standard seasonal retail scenario.",
  "periods": 20,
  "products": [
    "SKU_Basic",
    "SKU_Premium",
    "SKU_ShortLife"
  ],
  "locations": [
    "DC1",
    "DC2",
    "DC3",
    "DC4",
    "DC5"
  ],
  "shelf_life": {
    "SKU_Basic": 10,
    "SKU_Premium": 8,
    "SKU_ShortLife": 4
  },
  "lead_time": {
    "SKU_Basic": 0,
    "SKU_Premium": 0,
    "SKU_ShortLife": 0
  },
  "cold_capacity": {
    "DC1": 3956.5665970647583,
    "DC2": 3670.891167497476,
    "DC3": 3414.51847451406,
    "DC4": 2919.595530479684,
    "DC5": 2557.1025512044253
  },
  "cold_usage": {
    "SKU_Basic": 1.0,
    "SKU_Premium": 3.0,
    "SKU_ShortLife": 1.2
  },
  "production_cap": {
    "SKU_Basic": [
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800
    ],
    "SKU_Premium": [
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400
    ],
    "SKU_ShortLife": [
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500
    ]
  },
  "labor_cap": {
    "DC1": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC2": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC3": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC4": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC5": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ]
  },
  "labor_usage": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "return_rate": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "demand_curve": {
    "SKU_Basic": [
      280,
      324,
      286,
      327,
      415,
      599,
      609,
      820,
      1231,
      1278,
      1125,
      1113,
      1115,
      952,
      713,
      627,
      480,
      322,
      279,
      313
    ],
    "SKU_Premium": [
      137,
      171,
      183,
      157,
      206,
      298,
      320,
      501,
      508,
      704,
      716,
      692,
      599,
      496,
      321,
      284,
      204,
      181,
      181,
      172
    ],
    "SKU_ShortLife": [
      132,
      140,
      117,
      131,
      162,
      196,
      292,
      358,
      500,
      460,
      535,
      442,
      497,
      350,
      324,
      221,
      167,
      131,
      123,
      142
    ]
  },
  "demand_share": {
    "DC1": 0.25,
    "DC2": 0.2,
    "DC3": 0.2,
    "DC4": 0.2,
    "DC5": 0.15
  },
  "costs": {
    "lost_sales": {
      "SKU_Basic": 50.0,
      "SKU_Premium": 80.0,
      "SKU_ShortLife": 40.0
    },
    "inventory": {
      "SKU_Basic": 1.0,
      "SKU_Premium": 1.5,
      "SKU_ShortLife": 1.0
    },
    "waste": {
      "SKU_Basic": 2.0,
      "SKU_Premium": 3.0,
      "SKU_ShortLife": 2.0
    },
    "fixed_order": 0.0,
    "transshipment": 0.5,
    "purchasing": {
      "SKU_Basic": 10.0,
      "SKU_Premium": 20.0,
      "SKU_ShortLife": 15.0
    }
  },
  "constraints": {
    "moq": 0,
    "pack_size": 1,
    "budget_per_period": null,
    "waste_limit_pct": 0.02
  },
  "network": {
    "sub_edges": [
      [
        "SKU_Basic",
        "SKU_Premium"
      ]
    ],
    "trans_edges": []
  }
}
```

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB; import json
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that:
1. Parses the JSON data above (use json.loads on the string)
2. Models and solves the optimization problem
3. Prints status and objective value

Standard seasonal retail scenario.


[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v2

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA SCHEMA]
{
  "name": str,                          # scenario identifier
  "periods": int,                       # number of time periods
  "products": [str, ...],               # list of product IDs
  "locations": [str, ...],              # list of location IDs

  "shelf_life": {p: int},               # shelf life in periods per product
  "lead_time": {p: int},                # order lead time per product (0 = same-period arrival)

  "demand_curve": {p: [float, ...]},    # demand per product per period (0-indexed list)
  "demand_share": {l: float},           # fraction of total demand at each location

  "production_cap": {p: [float, ...]},  # max production per product per period (0-indexed list)
  "cold_capacity": {l: float},          # storage capacity per location
  "cold_usage": {p: float},             # storage units per unit of product

  "labor_cap": {l: [float, ...]},       # labor hours per location per period (0-indexed list)
  "labor_usage": {p: float},            # labor hours per unit sold
  "return_rate": {p: float},            # fraction of sales returned next period

  "costs": {
    "purchasing": {p: float},           # cost per unit ordered
    "inventory": {p: float},            # holding cost per unit per period
    "waste": {p: float},                # cost per unit expired
    "lost_sales": {p: float},           # penalty per unit of unmet demand
    "fixed_order": float,               # fixed cost per order placed
    "transshipment": float              # cost per unit transshipped
  },

  "constraints": {
    "moq": float,                       # minimum order quantity (0 = no MOQ)
    "pack_size": int,                   # order must be multiple of this (1 = no constraint)
    "budget_per_period": float|null,    # max purchasing cost per period
    "waste_limit_pct": float|null       # max waste as fraction of total demand
  },

  "network": {
    "sub_edges": [[p_from, p_to], ...], # substitution: p_from's demand can be served by p_to
    "trans_edges": [[l_from, l_to], ...]# transshipment: can ship from l_from to l_to
  }
}

[DATA ACCESS]
- The variable `data` is pre-loaded. Do NOT use file I/O.
- Lists are 0-indexed (period t in model uses index [t-1] in data arrays)

CRITICAL - Network edges require tuple conversion for Gurobi:
  sub_edges = [tuple(e) for e in data.get('network', {}).get('sub_edges', [])]
  trans_edges = [tuple(e) for e in data.get('network', {}).get('trans_edges', [])]

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that models and solves this optimization problem.

[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v2

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA]
The following JSON contains all instance data. Parse it directly in your code.

```json
{
  "name": "retail_f8_sustainability_v2",
  "description": "Standard seasonal retail scenario.",
  "periods": 20,
  "products": [
    "SKU_Basic",
    "SKU_Premium",
    "SKU_ShortLife"
  ],
  "locations": [
    "DC1",
    "DC2",
    "DC3",
    "DC4",
    "DC5"
  ],
  "shelf_life": {
    "SKU_Basic": 10,
    "SKU_Premium": 8,
    "SKU_ShortLife": 4
  },
  "lead_time": {
    "SKU_Basic": 0,
    "SKU_Premium": 0,
    "SKU_ShortLife": 0
  },
  "cold_capacity": {
    "DC1": 4351.845005463791,
    "DC2": 3058.9137264528454,
    "DC3": 3072.7274664757147,
    "DC4": 2622.5840718864783,
    "DC5": 2276.318626218026
  },
  "cold_usage": {
    "SKU_Basic": 1.0,
    "SKU_Premium": 3.0,
    "SKU_ShortLife": 1.2
  },
  "production_cap": {
    "SKU_Basic": [
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800
    ],
    "SKU_Premium": [
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400
    ],
    "SKU_ShortLife": [
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500
    ]
  },
  "labor_cap": {
    "DC1": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC2": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC3": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC4": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC5": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ]
  },
  "labor_usage": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "return_rate": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "demand_curve": {
    "SKU_Basic": [
      328,
      340,
      296,
      343,
      486,
      511,
      796,
      1029,
      989,
      1204,
      1487,
      1124,
      1181,
      850,
      641,
      477,
      432,
      377,
      314,
      329
    ],
    "SKU_Premium": [
      154,
      144,
      175,
      176,
      222,
      298,
      302,
      515,
      630,
      531,
      644,
      655,
      587,
      404,
      318,
      260,
      212,
      204,
      181,
      178
    ],
    "SKU_ShortLife": [
      119,
      131,
      138,
      133,
      150,
      221,
      314,
      319,
      463,
      571,
      461,
      485,
      486,
      404,
      253,
      212,
      194,
      143,
      122,
      122
    ]
  },
  "demand_share": {
    "DC1": 0.25,
    "DC2": 0.2,
    "DC3": 0.2,
    "DC4": 0.2,
    "DC5": 0.15
  },
  "costs": {
    "lost_sales": {
      "SKU_Basic": 50.0,
      "SKU_Premium": 80.0,
      "SKU_ShortLife": 40.0
    },
    "inventory": {
      "SKU_Basic": 1.0,
      "SKU_Premium": 1.5,
      "SKU_ShortLife": 1.0
    },
    "waste": {
      "SKU_Basic": 2.0,
      "SKU_Premium": 3.0,
      "SKU_ShortLife": 2.0
    },
    "fixed_order": 0.0,
    "transshipment": 0.5,
    "purchasing": {
      "SKU_Basic": 10.0,
      "SKU_Premium": 20.0,
      "SKU_ShortLife": 15.0
    }
  },
  "constraints": {
    "moq": 0,
    "pack_size": 1,
    "budget_per_period": null,
    "waste_limit_pct": 0.02
  },
  "network": {
    "sub_edges": [
      [
        "SKU_Basic",
        "SKU_Premium"
      ]
    ],
    "trans_edges": []
  }
}
```

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB; import json
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that:
1. Parses the JSON data above (use json.loads on the string)
2. Models and solves the optimization problem
3. Prints status and objective value

Standard seasonal retail scenario.


[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v3

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA SCHEMA]
{
  "name": str,                          # scenario identifier
  "periods": int,                       # number of time periods
  "products": [str, ...],               # list of product IDs
  "locations": [str, ...],              # list of location IDs

  "shelf_life": {p: int},               # shelf life in periods per product
  "lead_time": {p: int},                # order lead time per product (0 = same-period arrival)

  "demand_curve": {p: [float, ...]},    # demand per product per period (0-indexed list)
  "demand_share": {l: float},           # fraction of total demand at each location

  "production_cap": {p: [float, ...]},  # max production per product per period (0-indexed list)
  "cold_capacity": {l: float},          # storage capacity per location
  "cold_usage": {p: float},             # storage units per unit of product

  "labor_cap": {l: [float, ...]},       # labor hours per location per period (0-indexed list)
  "labor_usage": {p: float},            # labor hours per unit sold
  "return_rate": {p: float},            # fraction of sales returned next period

  "costs": {
    "purchasing": {p: float},           # cost per unit ordered
    "inventory": {p: float},            # holding cost per unit per period
    "waste": {p: float},                # cost per unit expired
    "lost_sales": {p: float},           # penalty per unit of unmet demand
    "fixed_order": float,               # fixed cost per order placed
    "transshipment": float              # cost per unit transshipped
  },

  "constraints": {
    "moq": float,                       # minimum order quantity (0 = no MOQ)
    "pack_size": int,                   # order must be multiple of this (1 = no constraint)
    "budget_per_period": float|null,    # max purchasing cost per period
    "waste_limit_pct": float|null       # max waste as fraction of total demand
  },

  "network": {
    "sub_edges": [[p_from, p_to], ...], # substitution: p_from's demand can be served by p_to
    "trans_edges": [[l_from, l_to], ...]# transshipment: can ship from l_from to l_to
  }
}

[DATA ACCESS]
- The variable `data` is pre-loaded. Do NOT use file I/O.
- Lists are 0-indexed (period t in model uses index [t-1] in data arrays)

CRITICAL - Network edges require tuple conversion for Gurobi:
  sub_edges = [tuple(e) for e in data.get('network', {}).get('sub_edges', [])]
  trans_edges = [tuple(e) for e in data.get('network', {}).get('trans_edges', [])]

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that models and solves this optimization problem.

[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v3

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA]
The following JSON contains all instance data. Parse it directly in your code.

```json
{
  "name": "retail_f8_sustainability_v3",
  "description": "Standard seasonal retail scenario.",
  "periods": 20,
  "products": [
    "SKU_Basic",
    "SKU_Premium",
    "SKU_ShortLife"
  ],
  "locations": [
    "DC1",
    "DC2",
    "DC3",
    "DC4",
    "DC5"
  ],
  "shelf_life": {
    "SKU_Basic": 10,
    "SKU_Premium": 8,
    "SKU_ShortLife": 4
  },
  "lead_time": {
    "SKU_Basic": 0,
    "SKU_Premium": 0,
    "SKU_ShortLife": 0
  },
  "cold_capacity": {
    "DC1": 3869.98377542635,
    "DC2": 3317.4833163625435,
    "DC3": 3284.9815973947448,
    "DC4": 2914.281722321398,
    "DC5": 2695.974507694342
  },
  "cold_usage": {
    "SKU_Basic": 1.0,
    "SKU_Premium": 3.0,
    "SKU_ShortLife": 1.2
  },
  "production_cap": {
    "SKU_Basic": [
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800
    ],
    "SKU_Premium": [
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400
    ],
    "SKU_ShortLife": [
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500
    ]
  },
  "labor_cap": {
    "DC1": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC2": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC3": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC4": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC5": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ]
  },
  "labor_usage": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "return_rate": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "demand_curve": {
    "SKU_Basic": [
      268,
      293,
      288,
      344,
      413,
      535,
      814,
      1006,
      1169,
      1061,
      1339,
      1126,
      1167,
      784,
      651,
      548,
      455,
      413,
      311,
      276
    ],
    "SKU_Premium": [
      130,
      175,
      172,
      183,
      224,
      272,
      375,
      483,
      591,
      670,
      676,
      581,
      551,
      476,
      304,
      235,
      198,
      195,
      184,
      151
    ],
    "SKU_ShortLife": [
      123,
      124,
      135,
      159,
      165,
      222,
      297,
      310,
      411,
      536,
      595,
      546,
      495,
      399,
      279,
      249,
      191,
      162,
      137,
      111
    ]
  },
  "demand_share": {
    "DC1": 0.25,
    "DC2": 0.2,
    "DC3": 0.2,
    "DC4": 0.2,
    "DC5": 0.15
  },
  "costs": {
    "lost_sales": {
      "SKU_Basic": 50.0,
      "SKU_Premium": 80.0,
      "SKU_ShortLife": 40.0
    },
    "inventory": {
      "SKU_Basic": 1.0,
      "SKU_Premium": 1.5,
      "SKU_ShortLife": 1.0
    },
    "waste": {
      "SKU_Basic": 2.0,
      "SKU_Premium": 3.0,
      "SKU_ShortLife": 2.0
    },
    "fixed_order": 0.0,
    "transshipment": 0.5,
    "purchasing": {
      "SKU_Basic": 10.0,
      "SKU_Premium": 20.0,
      "SKU_ShortLife": 15.0
    }
  },
  "constraints": {
    "moq": 0,
    "pack_size": 1,
    "budget_per_period": null,
    "waste_limit_pct": 0.02
  },
  "network": {
    "sub_edges": [
      [
        "SKU_Basic",
        "SKU_Premium"
      ]
    ],
    "trans_edges": []
  }
}
```

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB; import json
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that:
1. Parses the JSON data above (use json.loads on the string)
2. Models and solves the optimization problem
3. Prints status and objective value

Standard seasonal retail scenario.


[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v4

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA SCHEMA]
{
  "name": str,                          # scenario identifier
  "periods": int,                       # number of time periods
  "products": [str, ...],               # list of product IDs
  "locations": [str, ...],              # list of location IDs

  "shelf_life": {p: int},               # shelf life in periods per product
  "lead_time": {p: int},                # order lead time per product (0 = same-period arrival)

  "demand_curve": {p: [float, ...]},    # demand per product per period (0-indexed list)
  "demand_share": {l: float},           # fraction of total demand at each location

  "production_cap": {p: [float, ...]},  # max production per product per period (0-indexed list)
  "cold_capacity": {l: float},          # storage capacity per location
  "cold_usage": {p: float},             # storage units per unit of product

  "labor_cap": {l: [float, ...]},       # labor hours per location per period (0-indexed list)
  "labor_usage": {p: float},            # labor hours per unit sold
  "return_rate": {p: float},            # fraction of sales returned next period

  "costs": {
    "purchasing": {p: float},           # cost per unit ordered
    "inventory": {p: float},            # holding cost per unit per period
    "waste": {p: float},                # cost per unit expired
    "lost_sales": {p: float},           # penalty per unit of unmet demand
    "fixed_order": float,               # fixed cost per order placed
    "transshipment": float              # cost per unit transshipped
  },

  "constraints": {
    "moq": float,                       # minimum order quantity (0 = no MOQ)
    "pack_size": int,                   # order must be multiple of this (1 = no constraint)
    "budget_per_period": float|null,    # max purchasing cost per period
    "waste_limit_pct": float|null       # max waste as fraction of total demand
  },

  "network": {
    "sub_edges": [[p_from, p_to], ...], # substitution: p_from's demand can be served by p_to
    "trans_edges": [[l_from, l_to], ...]# transshipment: can ship from l_from to l_to
  }
}

[DATA ACCESS]
- The variable `data` is pre-loaded. Do NOT use file I/O.
- Lists are 0-indexed (period t in model uses index [t-1] in data arrays)

CRITICAL - Network edges require tuple conversion for Gurobi:
  sub_edges = [tuple(e) for e in data.get('network', {}).get('sub_edges', [])]
  trans_edges = [tuple(e) for e in data.get('network', {}).get('trans_edges', [])]

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that models and solves this optimization problem.

[SCENARIO]
Family: F8 (Omni channel and Store Operations)
Archetype: retail_f8_sustainability
Scenario ID: retail_f8_sustainability_v4

[BUSINESS DESCRIPTION]
Business narrative:
The retailer operates under a sustainability or regulatory constraint that limits total waste. Over the entire planning horizon, the total quantity discarded as waste must not exceed a fixed fraction of total demand. Demand is local and exogenous; unmet demand is lost and penalized. The retailer must balance serving demand, avoiding stockouts, and limiting waste.

Structure cues:
- The inventory and production structure is the same single-echelon system with storage capacity and lost sales as in the base scenario.
- Shelf life: Each product has a shelf life in periods. Inventory must be tracked by REMAINING LIFE.

  VARIABLE DEFINITION: I[p,l,t,r] = inventory at START of period t with r periods remaining.
  Convention: r=1 is OLDEST (sell first FIFO), r=shelf_life[p] is FRESHEST.

  KEY EQUATIONS - implement EXACTLY as written, do NOT add or remove terms:

  (1) Fresh inflow: I[p,l,t,SL] = Q[p,t] * demand_share[l]
      - This is ONLY the inflow from production. Do NOT subtract sales here!
      - Q is total production, demand_share distributes it to locations.

  (2) Aging: I[p,l,t+1,r] = I[p,l,t,r+1] - sales[p,l,t,r+1] for r=1..SL-1
      - Inventory tomorrow with r remaining = inventory today with r+1 remaining - sales

  (3) Waste: W[p,l,t] = I[p,l,t,1] - sales[p,l,t,1]
      - Items with r=1 that aren't sold become waste

  (4) Sales availability: sales[p,l,t,r] <= I[p,l,t,r]
      - Can only sell what you have in inventory

  (5) Inventory holding cost: charged on (I[p,l,t,r] - sales[p,l,t,r]) for r >= 2
      - Charge on END-of-period inventory (after sales), exclude expiring items (r=1)
- Storage capacity: sum over products of (cold_usage[p] * total_inventory[p,l,t]) <= cold_capacity[l]. These limits must be respected.
- The JSON specifies waste_limit_pct=0.02 (2%). Over the horizon, the total waste across all products, locations, and periods must not exceed 2% of total demand: sum(waste) <= 0.02 * sum(demand).
- Inventory is updated from previous stock and production, minus sales and waste, and remains non-negative.
- Substitution behavior remains active as defined in the JSON, and there is no transshipment.
- The objective is to minimize total cost (aggregating purchasing, holding, waste, and lost sales) subject to the global waste cap, making trade-offs between holding more inventory, losing sales, and discarding units explicit.

[DATA]
The following JSON contains all instance data. Parse it directly in your code.

```json
{
  "name": "retail_f8_sustainability_v4",
  "description": "Standard seasonal retail scenario.",
  "periods": 20,
  "products": [
    "SKU_Basic",
    "SKU_Premium",
    "SKU_ShortLife"
  ],
  "locations": [
    "DC1",
    "DC2",
    "DC3",
    "DC4",
    "DC5"
  ],
  "shelf_life": {
    "SKU_Basic": 10,
    "SKU_Premium": 8,
    "SKU_ShortLife": 4
  },
  "lead_time": {
    "SKU_Basic": 0,
    "SKU_Premium": 0,
    "SKU_ShortLife": 0
  },
  "cold_capacity": {
    "DC1": 4093.4018715811044,
    "DC2": 3982.907234711066,
    "DC3": 2758.6197526372707,
    "DC4": 2886.70990311586,
    "DC5": 2444.9246693708806
  },
  "cold_usage": {
    "SKU_Basic": 1.0,
    "SKU_Premium": 3.0,
    "SKU_ShortLife": 1.2
  },
  "production_cap": {
    "SKU_Basic": [
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800,
      800
    ],
    "SKU_Premium": [
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400,
      400
    ],
    "SKU_ShortLife": [
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500,
      500
    ]
  },
  "labor_cap": {
    "DC1": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC2": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC3": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC4": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ],
    "DC5": [
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0,
      99999.0
    ]
  },
  "labor_usage": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "return_rate": {
    "SKU_Basic": 0.0,
    "SKU_Premium": 0.0,
    "SKU_ShortLife": 0.0
  },
  "demand_curve": {
    "SKU_Basic": [
      298,
      329,
      310,
      402,
      466,
      493,
      772,
      978,
      971,
      1084,
      1490,
      1073,
      1094,
      864,
      640,
      468,
      398,
      342,
      375,
      300
    ],
    "SKU_Premium": [
      150,
      141,
      169,
      165,
      193,
      288,
      365,
      389,
      556,
      639,
      567,
      681,
      603,
      402,
      380,
      245,
      188,
      166,
      182,
      162
    ],
    "SKU_ShortLife": [
      118,
      112,
      120,
      143,
      190,
      198,
      247,
      336,
      393,
      500,
      579,
      437,
      444,
      376,
      256,
      205,
      189,
      151,
      126,
      111
    ]
  },
  "demand_share": {
    "DC1": 0.25,
    "DC2": 0.2,
    "DC3": 0.2,
    "DC4": 0.2,
    "DC5": 0.15
  },
  "costs": {
    "lost_sales": {
      "SKU_Basic": 50.0,
      "SKU_Premium": 80.0,
      "SKU_ShortLife": 40.0
    },
    "inventory": {
      "SKU_Basic": 1.0,
      "SKU_Premium": 1.5,
      "SKU_ShortLife": 1.0
    },
    "waste": {
      "SKU_Basic": 2.0,
      "SKU_Premium": 3.0,
      "SKU_ShortLife": 2.0
    },
    "fixed_order": 0.0,
    "transshipment": 0.5,
    "purchasing": {
      "SKU_Basic": 10.0,
      "SKU_Premium": 20.0,
      "SKU_ShortLife": 15.0
    }
  },
  "constraints": {
    "moq": 0,
    "pack_size": 1,
    "budget_per_period": null,
    "waste_limit_pct": 0.02
  },
  "network": {
    "sub_edges": [
      [
        "SKU_Basic",
        "SKU_Premium"
      ]
    ],
    "trans_edges": []
  }
}
```

[OUTPUT FORMAT]
- Import: import gurobipy as gp; from gurobipy import GRB; import json
- Set Gurobi params: m.Params.OutputFlag = 0; m.Params.Threads = 1; m.Params.Seed = 0
- Print at end:
  print(f"status: {{m.Status}}")
  if m.Status == 2:
      print(f"objective: {{m.ObjVal}}")
- Output ONLY executable Python code. No markdown, no explanations.

[TASK]
Write a GurobiPy script that:
1. Parses the JSON data above (use json.loads on the string)
2. Models and solves the optimization problem
3. Prints status and objective value

Standard seasonal retail scenario.