Timewindow costs
- Maura Lemaire
Per timewindow, a timewindow cost can be provided.
Some cases where this is particularly useful:
Inventory management problems in combinations with routing. For this a time dependent inventory cost/stockout cost is needed on the orders, which can be represented by adding a higher timewindow cost to timewindows where the risk of stockout is higher.
A timewindow is usually a hard constraint, but in some cases it is simply beneficial to plan for specific timewindows but to plan outside timewindows if required.
When the amount of orders is exceptionally high making it impossible to plan inside all the regular timewindows, then it might be better to allow 4 small timewindow violations then 2 large violations. This can be obtained by attaching the allocating well balanced timewindow costs to the orders.
Correlation to timewindows
When one timewindow has multiple timewindow costs, then that timewindow should not be represented by one timewindow but it should consists of separated (consecutive) timewindows for the corresponding timewindow costs to match. See examples.
Beware of conflicting input data. An exception will be thrown when multiple overlapping timewindows have different timewindow costs.
Syntax: a cost is indicated for each timewindow in the absolute timewindows field and similarly, different costs accorded to different timewindows are separated by the symbol &. When no cost is allocated to a specific timewindow, then a blank space indicates this.
In each of the timewindow fields, the same case is used as an example.
The delivery of goods to a supermarket. The supermarket is open for delivery between 06:00 and 20:00 but they prefer not to have the goods delivered between 10:00 and 19:00. For closure of the store to go smoothly, deliveries better not be supplied between 19:00 and 20:00 too, although this is still better then during the day. We want to attach an extra cost of 50 when supplying the store between 10:00-19:00 and 25 for deliveries in the evening, between 19:00-20:00. The supermarket is only operational on 2 days. Day 1 and day 2.