What does Little's Law describe?

Little's Law is a foundational principle in operations management that establishes a direct relationship among flow time, throughput, and work-in-process inventory within a system. Specifically, it articulates that the average number of items in a queuing system (work-in-process) is equal to the average throughput (item arrival rate) multiplied by the average flow time (the time it takes for an item to flow through the system).

This concept is critical for understanding how changes in one element—such as increasing throughput or altering flow time—can directly affect the other components. For instance, if one aims to reduce the flow time of products, it is likely to impact the amount of work-in-process inventory as well as the overall throughput.

Understanding Little's Law can help businesses optimize their processes, improve efficiency, and manage inventories more effectively, making it a crucial aspect of operations management.