Input

The goal of the picking optimisation solver is to create optimal routes and picking list for the workers in a warehouse. Consequently the first to do is to define the layout of the warehouse at the base of the problem.

Layout

Layouts of a warehouse are converted to graphs so that they can be used by routing algorithms .

670 — Simplified example of how we can convert warehouse layouts to graphs that can be used for routing algorithms.

Graph creation request

The graph creation request is structured as follows

Property	Type	Description
name	String	Name that describes the graph
edges	array of Edges	List of edges composing the graph
routingOptions	RoutingOptions	Object containing parameters used to tune how the Solver will handle the graph. If not specified the graph will be setup with the default values

Edges

The graph is uploaded as a list of edges where each edges contains information on the origin, destination and the weight.

Property	Type	Description
`from`	String	Source node of edge in the graph
`to`	String	Destination node of edge in the graph
`weight`	Number	Weight of the weighted directed edge. Usually the distance in meters

RoutingOptions

These parameters tell the Solver how to manage the congestion forecasting and the default speed of the pickers.

Property	Type	Description
lookaheadTime	String (duration iso8601)	How much the solver should look ahead to manage congestion
timeSegmentSize	String (duration iso8601)	Duration of the time segments in which the look ahead time is divided
graphUpdateMultiplier	Number	This parameter controls how non-blocking pickers influence the congestion on the graph
speedInMeterPerSecond	Number	Default speed for each picker

Example

Let's take the simple layout shown in the following image and let's see how it can be coded and uploaded.

2101 — Simple graph composed of 9 nodes representing a very simple warehouse layout.

The graph is composed of 9 nodes and 18 edges (since it can be navigated in both directions).

curl --request POST \
     --url https://onpick.solvice.io/graph/create \
     --header 'Accept: application/json' \
     --header 'Authorization: <<apiKey>>' \
     --header 'Content-Type: application/json' \
     --data '
     {
		"name" : "test",
		"edges" :	[
			{"from":"AA","to":"BA","weight":1.0},
			{"from":"BA","to":"AA","weight":1.0},
			{"from":"BA","to":"CA","weight":1.0},
			{"from":"CA","to":"BA","weight":1.0},
			{"from":"CA","to":"CB","weight":1.0},
			{"from":"CB","to":"CA","weight":1.0},
			{"from":"CB","to":"CC","weight":1.0},
			{"from":"CC","to":"CB","weight":1.0},
			{"from":"CC","to":"BC","weight":1.0},
			{"from":"BC","to":"CC","weight":1.0},
			{"from":"BC","to":"BB","weight":1.0},
			{"from":"BB","to":"BC","weight":1.0},
			{"from":"BA","to":"BB","weight":1.0},
			{"from":"BB","to":"BA","weight":1.0},
			{"from":"BC","to":"AC","weight":1.0},
			{"from":"AC","to":"BC","weight":1.0},
			{"from":"AC","to":"AB","weight":1.0},
			{"from":"AB","to":"AC","weight":1.0}
			]
	}
'

{
  "id":"6568e4d6-e3cf-4eec-8694-0ea7db75cebe",
  "createdAt":"2022-03-02T10:47:14.582766",
  "name": "test",
  "updatedAt":"2022-03-02T10:47:14.582838",
  "edges":18,
  "nodes":9,
  "username": "test",
  "routingOptions":{
    "lookaheadTime":900.000000000,
    "timeSegmentSize":300.000000000,
    "speedInMeterPerSecond":1.6,
    "graphUpdateMultiplier":1.5
  }
}

Response

The response provided for a successful upload presents some useful information regarding the uploaded graph.

Property	Type	Description
id	string (UUID)	The unique identifier that must be used to select this graph in a PickRequest
name	string	A name for the graph (currently unused)
edges	integer	The number of edges in the graph
nodes	integer	The number of nodes in the graph
createdAt	string (date)	The date when the graph was uploaded
updatedAt	string (date)	The date of the last update
username	string	Username of the user uploading the graph
routingOptions	RoutingOptions	If not specified in the request it will report the default values.