The Lecture Notes Blog

Little’s law


Little’s law was named after the American professor John Little (1950s). It defines the relationship between the inventory, the flow rate and the flow time, who have all been already defined previously.

inventory = number of flow units in the process
flow rate = rate at which flow units are being processed
flow time = time a single flow unit spends in the process

Little’s law: inventory (I) = flow Rate (R) * flow Time (T)

Little’s law is important, because it can help us calculate one of the three variables. Once two of the variables are known, the third one is set by the law. This also means that, form the standpoint of an executive, two variables can be picked by management while the third one then falls into place.

These lecture notes were taken during 2013 installment of the MOOC “An Introduction to Operations Management” taught by Prof. Dr. Christian Terwiesch of the Wharton Business School of the University of Pennsylvania at

1 Comment

  1. […] do? Did it add value to the process?), the last two sources of waste are really an expression of Little’s law. Some scholars point out that waste of intellect (ignoring the ideas of employees for problem […]

Leave a comment:

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: