Modeling and scheduling a flexible manufacturing cell with parallel processing capability

Traditionally, machine tools are able to process at most one operation on one part at a time provided they have only a single spindle and a single turret. Yet, with the advent of Turn-Mill machining centers carrying multiple spindles and turrets, parallel processing and multitask metal-cutting becomes possible. This paper deals with scheduling of a flexible manufacturing cell with parallel processing capability. This problem is first formulated as a mixed integer linear programming model. Using this model, small instances are solved for optimality. Then, to solve large instances, five metaheuristics are developed based on the proposed encoding scheme, operators and local search. Test cases are used to evaluate and compare the algorithms as well as the mathematical model.