Integration of hybrid additive/subtractive manufacturing planning and scheduling by metaheuristics

Reviewed solutions to model additive manufacturing process planning do not include all types of flexibility required by hybrid additive/subtractive operation. In the proposed system the features are extracted from CAD by a rule-oriented system denoting accessibility, surface accuracy, volume merging by functional relations, including deleted datum; the process planner identifies alternative modes to process the operation (operation flexibility) and allows swaps between operations in the routing sequence (sequencing flexibility); the system core generates a precedence graph of manufacturing features introducing flexibility by both conjunctive and disjunctive arcs and nodes, which can enter any position of a subsequence and ranks them by an antecedence analysis. Parametrized relation allows the precedence graph to be visited by a constructive metaheuristic. An Ant Colony Optimization (ACO) has been validated on properly designed instances and literature benchmarks varying job number, alternative operations and disjunctive arcs of routing. Current model reduces the node redundancy of AND/OR graphs and copes with the increased complexity of integrated process planning and job shop scheduling.