Multi-Purpose Machines

In a multi-purpose machine (MPM) model there is a set of machines µ _i (µ _ij ) ⊆ {M₁,... , M _m } associated with a job J _i (operation O _ij ). J _i (O _ij ) has to be processed by one machine in the set µ _i (µ _ij ). Thus, scheduling problems with multi-purpose machines combine assignment and scheduling problems: we have to schedule each job J _i (operation O _ij ) on exactly one machine from the set µ _i (µ _ij ).