Little's Law Calculator

Formula

The formula to calculate the average WIP (Work In Progress) using Little's Law is:

\[ L (WIP) = λ \times W \]

Where:

\( L \) is the average number of items within the system (WIP)
\( λ \) is the arrival rate/output rate of items into the system
\( W \) is the average time an item spends in the system

This formula can also be simplified to:

\[ WIP = T \times LT \]

Where:

\( WIP \) is the Work In Progress
\( T \) is the throughput
\( LT \) is the lead time

What is Little's Law?

Little's Law is a principle in queuing theory that states the average number of items within a system (Work In Progress) is equal to the product of the arrival rate (or output rate) of items and the average time an item spends in the system. This law is useful in analyzing the performance of processes and systems to identify bottlenecks and optimize operations.

Example Calculation

Let's consider an example:

Arrival/Output Rate (λ): 10 items/hour
Average Time in System (W): 2 hours

Using the formula to calculate WIP:

\[ WIP = 10 \times 2 = 20 \, \text{items} \]

This shows that with an arrival rate of 10 items per hour and an average time in the system of 2 hours, the average number of items in progress within the system is 20 items.