Input

The goal of the picking optimisation solver is to find the best picklist and route for each picker.
To do so, the characteristics of each picker and item to pick need to be provided in the request.

Pick solve request

Here is the general structure of the solve request.

Property	Type	Description
`graph`	string (UUID)	The graph id returned by OnPick platform when uploaded.
`pickers`	array of pickers	The list of pickers that will retrieve the items in the warehouse.
`picks`	array of picks	The list of picks.

Pickers

Pickers are specified as a list of objects with the following properties

Property	Type	Description
`name`	string	Unique name identifier for the picker.
`position`	string	Node name for the initial position of the picker in the graph.
`capacity`	integer	Capacity of the picker
`timeCapacity`	string (duration iso8601)	The time the picker has to complete his picklist, expressed as a duration.
`speed`	double	The speed of the picker expressed in meters per second. If not specified it is assumed to be the one specified in the routing options for the graph which has a default value of 1.6 m/s
`blocking`	boolean	If true it signals the solver that other pickers cannot walk around this picker. For instance they may operate a vehicle (e.g. a forklift) or large picking device and walking around them may be dangerous or unfeasible.
`dropOff`	string	The position where the pickers should drop off the picks.

Picks

Picks have the following properties

Property	Type	Description
`name`	string	Unique name identifying the item
`position`	string	Name of the node corresponding to the position of the item.
`pickHandlingDuration`	string (duration iso8601)	The time needed to pick the item from the shelf.
`load`	integer	How much picker capacity the item is going to use.
`picker`	string	If specified indicates the Picker that is assigned to pick this item.
`customer`	string	If specified indicates the unique identifier of the customer order linked to this item.

Example

For the example we are using the demo graph with id="00000000-0000-0000-0000-000000000000"

curl --request POST --url https://onpick.solvice.io/pick/solve \
		 -H "Authorization: <<apiKey>>" \
     --data '
{
     "graph": "00000000-0000-0000-0000-000000000000",
     "pickers": [
          {
               "name": "John",
               "position": "node-1-1"
          }
     ],
     "picks": [
          {
               "name": "p1",
               "position": "node-4-3",
               "pickHandlingDuration": "PT1S"
          },
          {
               "name": "p2",
               "position": "node-5-2",
               "pickHandlingDuration": "PT1S"
          }
     ]
}
'

{
    "solution": [
      {
        "picker" : "John",
        "visits" : [
            {
                "position": "node-1-1",
                "pick": null,
                "arrival": 0.0,
                "arrivalInSeconds": 0,
                "nextPosition": "node-4-3",
                "path": [
                    "node-1-1",
                    "node-1-2",
                    "node-1-3",
                    "node-2-3",
                    "node-3-3",
                    "node-4-3"
                ]
            },
            {
                "position": "node-4-3",
                "pick": "p1",
                "arrival": 125.000000000,
                "arrivalInSeconds": 125,
                "nextPosition": "node-5-2",
                "path": [
                    "node-4-3",
                    "node-3-3",
                    "node-2-3",
                    "node-1-3",
                    "node-1-2",
                    "node-2-2",
                    "node-3-2",
                    "node-4-2",
                    "node-5-2"
                ]
            },
            {
                "position": "node-5-2",
                "pick": "p2",
                "arrival": 394.000000000,
                "arrivalInSeconds": 394,
                "nextPosition": null,
                "path": null
            }
        ]
    }],
    "totalDistance": 361,
    "unassigned" : []
}

Pick response

The solution returned by OnPick is structured as follows:

Property	Type	Description
solution	array of PickerRoute objects	The solution contains the detailed route for each picker
totalDistance	integer	The total distance travelled by the pickers
unassigned	array of picks	If the solver was unable to assign all the picks it will report the unassigned picks in this array.3

As shown in the table, the solution property contains an array of PickerRoute objects. Each PickerRoute contains two properties, picker and visits. Picker returns the name of the picker and visits is an array of Position objects. Each Position contains information on the current position (if there is a pick or not) and how to reach the next position until all the picks are collected.

Property	Type	Description
position	string	The node in the graph that represents the current position of the picker
pick	string	If not null, it specifies the item the picker should collect in this position
arrival	float	Estimated arrival time in this position
arrivalInSeconds	integer	Estimated arrival time in seconds
nextPosition	string	The next node in the route of the Picker
path	array of string	The nodes that the Picker should go through to arrive to nextPosition