An unrelated parallel machines model for an industrial production resetting problem

Efficient production resettings are necessary to achieve production flexibility. For this reason, most modern companies are trying to reduce the setup time required to switch the production from one product type to another. One way to minimise these times is to schedule correctly the various tasks involved during a production resetting: changing tools, modifying each machine setting, etc. In this paper, we present how this problem can be identified to an unrelated parallel machines problem with release dates and delivery times where the resources are operators. We show that the data structure allows simplifying the problem into an assignment problem, even when we take into consideration the availability constraints of the operators. A branch-and-bound method is presented which has been tested on industrial and generated instances. [Received 6 February 2007; Revised 22 August 2007; Accepted 11 November 2007]