Data Schema

{
  "$schema": "http://json-schema.org/draft-07/schema#",
  "title": "SydneyMetroPossessionPlanningSchema",
  "description": "Data schema for heavy rail possession optimization, incompatibility matrix clash detection, and Environmental Protection Licence (EPL) compliance.",
  "type": "object",
  "properties": {
    "PossessionEvent": {
      "type": "object",
      "properties": {
        "possession_id": {
          "type": "string",
          "description": "Unique UUID for the planned possession window."
        },
        "status": {
          "type": "string",
          "enum": [
            "T-52_Draft",
            "T-26_Locked",
            "T-12_Final",
            "Active",
            "Handed_Back",
            "Cancelled"
          ],
          "description": "Current status in the Network Rail standard T-countdown process."
        },
        "time_window": {
          "type": "object",
          "properties": {
            "start_time": {
              "type": "string",
              "format": "date-time"
            },
            "end_time": {
              "type": "string",
              "format": "date-time"
            },
            "wrench_time_minutes": {
              "type": "integer",
              "description": "Total duration available after deducting CBTC isolation and testing handback procedures."
            }
          },
          "required": [
            "start_time",
            "end_time",
            "wrench_time_minutes"
          ]
        },
        "spatial_limits": {
          "type": "object",
          "properties": {
            "start_chainage_km": {
              "type": "number"
            },
            "end_chainage_km": {
              "type": "number"
            },
            "line_segment": {
              "type": "string"
            },
            "track_id": {
              "type": "string",
              "enum": [
                "UP",
                "DOWN",
                "BOTH"
              ]
            },
            "noise_catchment_area": {
              "type": "string"
            }
          },
          "required": [
            "start_chainage_km",
            "end_chainage_km",
            "line_segment"
          ]
        },
        "stacked_tasks": {
          "type": "array",
          "items": {
            "$ref": "#/definitions/MaintenanceTask"
          },
          "description": "List of all compatible maintenance tasks clustered within this specific possession."
        }
      },
      "required": [
        "possession_id",
        "status",
        "time_window",
        "spatial_limits",
        "stacked_tasks"
      ]
    }
  },
  "definitions": {
    "MaintenanceTask": {
      "type": "object",
      "properties": {
        "task_id": {
          "type": "string"
        },
        "task_type": {
          "type": "string",
          "enum": [
            "Tamping",
            "OHL_Repair",
            "CBTC_Balise_Testing",
            "Rail_Grinding",
            "Vegetation_Clearance",
            "Station_Fitout"
          ]
        },
        "contractor_id": {
          "type": "string"
        },
        "requires_electrical_isolation": {
          "type": "boolean",
          "description": "True if the task requires traction power isolation under ENSR compliance."
        },
        "mobile_plant_deployed": {
          "type": "boolean",
          "description": "True if MEWP, RRV, or excavators are deployed, requiring rigid Safe Approach Distance (SAD) enforcement."
        },
        "environmental_impact": {
          "type": "object",
          "properties": {
            "predicted_LAmax_dB": {
              "type": "number"
            },
            "predicted_LAeq_dB": {
              "type": "number"
            },
            "vibration_risk": {
              "type": "string",
              "enum": [
                "Low",
                "Medium",
                "High"
              ]
            }
          },
          "description": "Acoustic parameters required for cumulative EPL compliance calculations."
        },
        "incompatibility_tags": {
          "type": "array",
          "items": {
            "type": "string"
          },
          "description": "Tags utilized by the incompatibility matrix to prevent spatial clashes (e.g., 'VIBRATION_SOURCE', 'LIVE_WIRE_HAZARD', 'CBTC_DISRUPTION')."
        }
      },
      "required": [
        "task_id",
        "task_type",
        "requires_electrical_isolation",
        "environmental_impact"
      ]
    }
  }
}