# Flexible Job Shop with Preemption

I'm trying to solve a flexible job shop problem variant that has precedence constraints on jobs along with a few other issues. We have a MIP formulation and also a simulated annealing algorithm to solve at the moment. But now we would like to allow preemption of jobs (leaving a job and coming back to finish it later, possibly times).
Do you have any thoughts on how to model the problem to allow for preemption?

• Would you please, what you mean by how to model the problem to allow for preemption? Would you need to model it in the MP or by using the SA algorithm? In the first case, there are lots of papers to do that. – A.Omidi Oct 31 '20 at 12:25
• Are there complications such as tear-down and set-up costs for each preemption, or periods during a job when preemption is not allowed – Ray Butterworth Oct 31 '20 at 13:56