A graph-based constraint programming approach for the integrated process planning and scheduling problem

Integration of process planning and scheduling (IPPS) is to carry out both functions simultaneously. This paper provides a graph-based constraint programming (GCP) approach to solve the type-2 IPPS problem that takes AND/OR graphs as input. The proposed GCP approach is implemented based on the IBM ILOG CP Optimizer. AND/OR graph is tailored to cope with IPPS instances. Directed arcs define both precedence and presence relationships. The or-link, a set of mutually-exclusive operations, is defined to represent alternative process routes. Interval variables and scheduling-oriented constraints are adopted to project the IPPS-specific AND/OR graph to a concise CP model with which minimizing makespan is incorporated as the objective. The GCP approach is tested on a set of benchmark problems. Experimental results show that the proposed approach outperforms compared algorithms on major IPPS instances. (C) 2021 Elsevier Ltd. All rights reserved.

Automated summary

This paper presents a graph-based constraint programming approach to solve the integration of process planning and scheduling problem, implemented based on IBM ILOG CP Optimizer. Experimental results show that the proposed approach outperforms compared algorithms on major IPPS instances.