Evaluation of Value Time Sequencing Rules in a Real World Job Shop

This paper reports a case study carried out in an Engineering industry manufacturing nineteen types of products against orders. The objective of this research was to select the sequencing rule that will optimise the combined performance of work-in-process inventory in monetary terms and delivery performance. Past studies in this area show that rules based on either the value of the orders or the value-processing time of the orders have not been investigated. This study evaluates the performance of the two sequencing rules based on the value and processing time of the orders: (i) Lowest Value Time rule (LVT) (ii) Highest Value Time rule (HVT). Incidental to this study, a few other sequencing rules were evaluated. To carry out the investigations, a simulator using GPSS (General Purpose Simulation System) was developed.