On an Integer Multicommodity Flow Problem from the Airplane Industry y

Here we discuss a new integer multicommodity ow problem in which the commodities can not be shipped independently. The problem emerges in the routing of airplane parts from production sites to assembly sites. The parts are of such size that they have to be carried on dedicated trailers. Each type of part has its own type of trailer. A part is loaded on its trailer after it is produced, carried on its trailer to its assembly site, and then the trailer has to be recycled. The transport of the parts is done with huge specially built transportation aircrafts. For reasons of stability such aircrafts can only carry some pre-speci ed combinations of parts on trailers and empty trailers. We consider the problem of nding a feasible transportation plan that minimises the total ying time of the transportation aircrafts. For this purpose we develop both optimisation and approximation algorithms.