Effect of errors and delays in inventory reporting on production system performance

A discrete linear control representation has been used by the authors to examine the performance of multi-level, multi-product production control systems operating in an environment where system errors are expected. Production control systems operate in an uncertain environment. Besides the commonly considered uncertainties in demand, yield, quality and delivery times, errors frequently exist in basic data such as bills of materials and occur in stock records as a result of incorrect or late transaction recording. This paper presents the basic discrete linear control representation of MRP and ROC systems, shows how these representations may be modified to include certain types of internal system error, before examining the effects of delays in stock recording and of recording errors on the performance of the system. Performance measures include the effects on schedules, planned stock and delivery performance.