A Research On Freezing The Master Production Schedule System Based On ANOVA

Master Production Schedule (MPS) plays a vital role in a company's daily operations management. Minor changes in higher level MRP records or MPS usually results in significant changes in MRP plans, which in turn causes inventory costs increase and disruption in production. This issue is identified as MRP nervousness or instability.Blackburn, Kropp and Mille(r1985)[5] has studied 5 methods for reducing MRP nervousness, this paper uses the method of freezing the MPS - the most commonly used method study the impact of MPS freezing parameters upon total cost and schedule instability in a multilevel MRP system.This paper investigates the impact of freezing parameters and their interactions upon system performance and the selection of environmental factors using ANOVA method. Two models are built to simulate the above systems under deterministic demand and under demand uncertainty respectively. The first model focuses on the impact of freezing MPS on the total cost and total instability in multilevel MRP system under deterministic demand. The results show that freezing parameters are significantly influenced by product structure, cost parameters as well as lot-sizing rules. The second model investigates the impact of freezing the MPS on the total cost, total instability and service level in multilevel MRP systems under demand uncertainty. The conclusions reveal that freezing parameters are influenced by forecasting errors. This paper extends the previous research on single-level MRP systems to multilevel. Some valuable conclusions are reached and can be considered by industrial practitioners when freezing the MPS is used to improve the overall performance of MRP systems.