成本模型參數

歐洲經濟區 (EEA) 開發人員

OptimizeToursRequest 訊息 (RESTgRPC) 包含多項與費用相關的屬性。這些費用參數共同代表要求的費用模式。成本模型會擷取許多要求的高階最佳化目標,例如:

  • 優先選擇較快的路線 Vehicle,而非較短的路線,反之亦然
  • 判斷遞送 Shipment 的成本是否值得 Shipment 完成的價值
  • 僅在符合成本效益時,才在時間範圍內取貨和送貨

查看含費用的要求範例

{
  "model": {
    "globalStartTime": "2023-01-13T16:00:00-08:00",
    "globalEndTime": "2023-01-14T16:00:00-08:00",
    "shipments": [
      {
        "deliveries": [
          {
            "arrivalLocation": {
              "latitude": 37.789456,
              "longitude": -122.390192
            },
            "duration": "250s"
          }
        ],
        "pickups": [
          {
            "arrivalLocation": {
              "latitude": 37.794465,
              "longitude": -122.394839
            },
            "duration": "150s"
          }
        ],
        "penaltyCost": 100.0
      },
      {
        "deliveries": [
          {
            "arrivalLocation": {
              "latitude": 37.789116,
              "longitude": -122.395080
            },
            "duration": "250s"
          }
        ],
        "pickups": [
          {
            "arrivalLocation": {
              "latitude": 37.794465,
              "longitude": -122.394839
            },
            "duration": "150s"
          }
        ],
        "penaltyCost": 5.0
      },
      {
        "deliveries": [
          {
            "arrivalLocation": {
              "latitude": 37.795242,
              "longitude": -122.399347
            },
            "duration": "250s"
          }
        ],
        "pickups": [
          {
            "arrivalLocation": {
              "latitude": 37.794465,
              "longitude": -122.394839
            },
            "duration": "150s"
          }
        ],
        "penaltyCost": 50.0
      }
    ],
    "vehicles": [
      {
        "endLocation": {
          "latitude": 37.794465,
          "longitude": -122.394839
        },
        "startLocation": {
          "latitude": 37.794465,
          "longitude": -122.394839
        },
        "costPerHour": 40.0,
        "costPerKilometer": 10.0
      }
    ]
  }
}
    

Vehicle 費用屬性

Vehicle 訊息 (RESTgRPC) 具有多個費用屬性:

  • Vehicle.cost_per_hour:代表每小時的車輛營運成本,包括交通、等待、拜訪和休息時間。
  • Vehicle.cost_per_kilometer:代表車輛每行駛一公里的成本。
  • Vehicle.cost_per_traveled_hour:代表車輛在運輸期間的營運成本,不包括等待、拜訪和休息時間。

最佳化工具會根據這些費用參數,在時間與行駛距離之間做出取捨。最佳化路線產生的費用會顯示在回應訊息中,如 metrics.costs 所示:

costPerHour 增加時,最佳化工具會嘗試尋找較快的路線,這些路線可能不是最短的路線。在這個範例中,最快的路線剛好也是最短的路線,因此成本參數的變更影響不大。

Shipment 費用屬性

Shipment 訊息 (RESTgRPC) 也有幾個費用參數:

  • Shipment.penalty_cost 代表略過運送所產生的費用。設定貨件的 penalty_cost 參數會使貨件成為必要貨件,也就是說,只有在指定限制無法完成貨件時,系統才會略過貨件。
  • Shipment.VisitRequest.cost 代表特定取貨或送貨的費用,主要用於在單一貨件的多個取貨或送貨選項之間,進行費用取捨。

Shipment 費用參數使用的無量綱單位與 Vehicle 費用參數相同。完成 Shipment 所產生的費用超過其處罰費用,則任何 Vehicle 的路徑都不會包含 Shipment,而是會顯示在回應訊息的 skipped_shipments 清單中。

ShipmentModel 費用屬性

ShipmentModel 訊息 (RESTgRPC) 包含單一費用屬性 globalDurationCostPerHour。這項費用是根據所有車輛完成 ShipmentRoute 所需的總時間計算。提高 globalDurationCostPerHour 可優先完成所有出貨作業。

路徑最佳化回應的成本屬性

OptimizeToursResponse 訊息 (RESTgRPC) 具有代表完成 ShipmentRoute 時所產生費用的成本屬性。metrics.costsmetrics.totalCost 屬性代表回應中所有路徑產生的費用單位數。每個 routes 項目都有 routeCosts 和 屬性,代表該特定路線的費用。routeTotalCosts

查看含費用的範例要求回應

{
  "routes": [
    {
      "vehicleStartTime": "2023-01-14T00:00:00Z",
      "vehicleEndTime": "2023-01-14T00:28:22Z",
      "visits": [
        {
          "isPickup": true,
          "startTime": "2023-01-14T00:00:00Z",
          "detour": "0s"
        },
        {
          "shipmentIndex": 2,
          "isPickup": true,
          "startTime": "2023-01-14T00:02:30Z",
          "detour": "150s"
        },
        {
          "startTime": "2023-01-14T00:08:55Z",
          "detour": "150s"
        },
        {
          "shipmentIndex": 2,
          "startTime": "2023-01-14T00:21:21Z",
          "detour": "572s"
        }
      ],
      "transitions": [
        {
          "travelDuration": "0s",
          "waitDuration": "0s",
          "totalDuration": "0s",
          "startTime": "2023-01-14T00:00:00Z"
        },
        {
          "travelDuration": "0s",
          "waitDuration": "0s",
          "totalDuration": "0s",
          "startTime": "2023-01-14T00:02:30Z"
        },
        {
          "travelDuration": "235s",
          "travelDistanceMeters": 795,
          "waitDuration": "0s",
          "totalDuration": "235s",
          "startTime": "2023-01-14T00:05:00Z"
        },
        {
          "travelDuration": "496s",
          "travelDistanceMeters": 1893,
          "waitDuration": "0s",
          "totalDuration": "496s",
          "startTime": "2023-01-14T00:13:05Z"
        },
        {
          "travelDuration": "171s",
          "travelDistanceMeters": 665,
          "waitDuration": "0s",
          "totalDuration": "171s",
          "startTime": "2023-01-14T00:25:31Z"
        }
      ],
      "metrics": {
        "performedShipmentCount": 2,
        "travelDuration": "902s",
        "waitDuration": "0s",
        "delayDuration": "0s",
        "breakDuration": "0s",
        "visitDuration": "800s",
        "totalDuration": "1702s",
        "travelDistanceMeters": 3353
      },
      "routeCosts": {
        "model.vehicles.cost_per_kilometer": 33.53,
        "model.vehicles.cost_per_hour": 18.911111111111111
      },
      "routeTotalCost": 52.441111111111113
    }
  ],
  "skippedShipments": [
    {
      "index": 1
    }
  ],
  "metrics": {
    "aggregatedRouteMetrics": {
      "performedShipmentCount": 2,
      "travelDuration": "902s",
      "waitDuration": "0s",
      "delayDuration": "0s",
      "breakDuration": "0s",
      "visitDuration": "800s",
      "totalDuration": "1702s",
      "travelDistanceMeters": 3353
    },
    "usedVehicleCount": 1,
    "earliestVehicleStartTime": "2023-01-14T00:00:00Z",
    "latestVehicleEndTime": "2023-01-14T00:28:22Z",
    "totalCost": 57.441111111111113,
    "costs": {
      "model.vehicles.cost_per_kilometer": 33.53,
      "model.vehicles.cost_per_hour": 18.911111111111111,
      "model.shipments.penalty_cost": 5
    }
  }
}
    

在範例回應中,頂層 metrics.costs 為:

{
  "metrics": {
    ...
    "costs": {
      "model.vehicles.cost_per_hour": 18.911111111111111,
      "model.vehicles.cost_per_kilometer": 33.53,
      "model.shipments.penalty_cost": 5
    }
  }
}

model.shipments.penalty_cost 值代表因貨運遭略過而產生的費用。skippedShipments 屬性會列出已略過的貨件。

在本例中,系統只會略過範例要求中的 model.shipments[1]model.shipments[1] 的違規費用為 5 個單位,與範例回應中的 model.shipments.penalty_cost 鍵相符。與 Vehicle 的 40.0 costPerHour 和 10.0 costPerKilometer 相比,這批貨物的低 penaltyCost 使得跳過這批貨物比完成這批貨物更具成本效益。

進階主題:費用和軟性限制

多個 OptimizeToursRequest 訊息 (RESTgRPC) 屬性代表軟性限制,也就是無法滿足時會產生費用的限制。

舉例來說,車輛 LoadLimit (RESTgRPC) 限制具有 softMaxLoadcostPerUnitAboveSoftMax 屬性。這些費用加總後,會與超出 softMaxLoad 的負載單位成正比,因此只有在從成本角度來看有意義時,才會超出限制。

同樣地,TimeWindow 限制 (RESTgRPC) 具有 soft_start_timesoft_end_time 屬性,並會根據受限事件相對於 TimeWindow 的發生時間 (早或晚) 產生對應的 cost_per_hour_before_soft_start_timecost_per_hour_after_soft_end_time

與所有成本模型參數一樣,軟性限制成本會以與其他成本參數相同的無因次單位表示。

LoadLimit 限制條件會在「負載需求和限制」中詳細說明。TimeWindow 限制會在「取貨和送貨時間範圍限制」一文中詳細說明。