Process Sequencing for Features with Multiple Processing Requirements

Abstract

Process sequencing is a part of process planning that generate the sequence of processes need to manufacture part. Process sequencing is performed with a goal to minimize time and/or cost of manufacturing. In this paper we elaborate of issues and algorithms for process sequencing under condition that manufacturing features that constitute the part require several distinct processes. This condition is very common in practice, particularly for parts with stricter tolerance requirements. For example, holes may require drilling and boring and/or reaming operations, slots and pockets are usually machined by rough and finish milling operations. Further, for more stricter tolerance grinding operations may be necessary. However, not many researchers addressed those requirements in process sequencing procedures. In the paper we briefly explain how multiple processes are generated for high tolerance features and develop an extended feature precedence network (FPN) which constrains the process sequencing algorithms. The extended feature precedence network and process alternatives for each feature are input for the process sequencing algorithms. From this data we generate the process plan network (PPN) and then we apply two procedures for process sequencing, space search algorithm and generalized traveling salesman problem (GTSP) algorithm in order to obtain the optimal sequences.