Vehicle RoutingVehicle Routing

Service Delivery in the FieldService Delivery in the Field

Clarke-Wright AlgorithmClarke-Wright Algorithm

Objective: Create a route that minimizes distance Objective: Create a route that minimizes distance (time) traveled from a depot to several customers.(time) traveled from a depot to several customers.

Net savings SNet savings Sij ij by linking two locations I and j.by linking two locations I and j.

Routes can be constrained (e.g. vehicle capacity) or Routes can be constrained (e.g. vehicle capacity) or unconstrained.unconstrained.

ijjiij CCCS 00

Steps in C-W AlgorithmSteps in C-W Algorithm

Construct a shortest-distance half-matrix.Construct a shortest-distance half-matrix. Assign one round-trip to each location.Assign one round-trip to each location. Calculate the net savings for each pair of outlying Calculate the net savings for each pair of outlying

locations, and enter them in a net savings half-locations, and enter them in a net savings half-matrix.matrix.

Enter values for trip indicator T (2 for round trip, 1 Enter values for trip indicator T (2 for round trip, 1 for one way, and 0 for no travel) into appropriate for one way, and 0 for no travel) into appropriate cells of the half-matrix.cells of the half-matrix.

Identify the cell with the maximum net saving and Identify the cell with the maximum net saving and link the locations provided Tlink the locations provided T>0, locations not >0, locations not already on a route, and other constrains are met.already on a route, and other constrains are met.