Some perspectives on the application of Little's law: L = λW

摘要

Little's law, L = λW, has been covered in operations management, operations research and management for decades. The expression has been applied to manufacturing and service processes, queueing models, inventory and other related problems. Although random characteristics of interarrival and processing times have been considered in the proof of the theorem, in the application of Little's theorem process variation, random characteristics and data homogeneity are often ignored. The purpose of this research is to show that the assumption of a steady-state condition in the application of Little's law theorem will shift the focus from the underlying process variation and may lead to incorrect decisions regarding the process parameters. It is recommended that Shewhart control charts be used to establish data homogeneity before the application of Little's law expression.