Refill on the road

[Bernd Welter]

I've been asked for the following requirement and whether / how to modell this in xTour2:

Generic setup:
blue truck - central depot
gray trucks: small refill stations

Based on a central depot the orders in the planning area require two types of material:

• 10-20% of the orders require material which is available only at the blue depot
• 80-90% of the orders require material which is available at the blue and the gray locations

Refills are required because

• The overall volume of orders exceeds the vehicle's capacity
• Time constraints apply such as maximum tour period or vehicle's operating intervals.

By utilizing the gray locations as alternative pickup depots the customers expect a huge potential of savings because the vehicles do not have to drive back to the blue depot.

Scenario	Traveltime in hh:mm	Distance	Tours / trips
#1 - from home	10:05	605 km	2 / 7
#2 - on road / from scratch	08:48	527 km	2 / 7
#3a - from nearest depot	10:22	622 km	2 / 7
#3b - with input plan "3a"	08:42	522 km	2 / 7

Here are the scenarios:

• Scenario 1 : no utilization of the gray locations

  

  #1 refill at the central depot

• Scenario 2 : refill on the road based on "from scratch" planning

  

  Scenario #2: Refill on the road from scratch (no input plan used)

• Scenario 3 : the gray locations are used for refilling "on the road"

  

  Scenario 3a: From the nearest depot

  

  #3b: refill on the road (graytrucks are the refill stations)

• Comparison in terms of monetary costs:

  

  Comparison

Sidenote:
Scenario 3 was built on a small iteration:

• I created an initial solution based on "each order has to be served by the closest depot" (scenario #2)
• Then I used the output plan as input plan for a planning with AlternativePickup and allowed each available location as refill location

Bernd