I have 3 factory plants a Producer, a Storage facility and a Maintenance facility.
To move goods or tools between the facilities a truck is needed, it is requested by the producer factory when a truck with a bike leaves for storage. For the producer to produce bikes it needs a truck from the start of production as the bike is assembled inside the truck, when it is finished the truck takes it to Storage which goes through a service time unloading before the truck can move off to another job or park up.
Neither the Storage or the Factory have any queuing space for a full truck so once one has gone into storage and is being unloaded another truck cannot be sent from the producer factory while one is being unloaded.
However empty trucks can be parked at the Maintenance facility with a capacity of 9. The Producer has a maintenance regime and must undergo maintenance every 100 hours of production at this time tools in a truck are shipped to the producer from the Maintenance Facility, when the Producer is maintained it results in wastage having to be taken to the storage facility and stored also and the tools to be taken back to the Maintenance facility but while the tools are in use the truck cannot leave to do other jobs. Bike production takes 6 hours and storage takes 2, maintenance takes 5 hours. Both the Producer and the Storage also can have random failures which require tools these have to be sent via trucks from the Maintenance facility and returned when finished but the truck cannot leave the tools to complete other jobs. The travel between any facility is half a hour, and when the producer requests a truck it must arrive within 2 hours? The trucks also receive maintenance at the Maintenance facility when they breakdown randomly.
I want to minimise the number of trucks I need, is it possible to model this with Xpress?
The numbers aren't important they are just made up I'm keen to know about how to model the process in Xpress.