Critical path analysis using simulation techniques and selection of lean tools to multiple critical paths based on cost factor

Abstract

A production system converts raw materials into finished goods by various processes. The processes could occur parallel in order to reduce the time taken to complete the processes. Critical path in production systems is the maximum time taken to complete processes occurring in parallel. Identifying critical paths are important because, in order to improve the cycle time emphasis needs to be given to the critical path. Critical path is usually a single path in deterministic processing times. Due to variability more than one path might tend to be critical within the same system. The initial part of this research focuses on identifying changes in critical paths in variable processing times and prioritization of paths. Several metrics such as critical path severity index, all path severity indexes, probability of critical path beyond standard time are used to identify the criticality of paths. Next, suitable tools are implemented within these paths in order to improve the probability of completion and reduce the costs due to delay. An economic analysis for using lean tools within the paths is done. The allocation of improvement tools is based on the variability of each process and the processing time