Glossary
Littles Law
In Queuing Theory, the most famous law is Littles Law, which asserts that the average number of customers in a queuing system is equal to the rate at which customers arrive. Used in Lean Manufacturing the principle aims to minimise waste and increase speed. Increasing speed equates to reducing lead-time to an organisations customers. Minimising waste includes an analysis of inventory and steps to reduce that inventory. Littles Law provides an equation of lead time equals WIP units divided by the Average Completion Rate in units per time period. By knowing any two variables within the equation allows the calculation of the third. For example, by reducing WIP whilst at the same time maintaining the same Average Completion Rate reduces lead time and so it goes. This rule applies to any process where that be manufacturing, transactional, service or design.