Throughput Time(TPT) is a Lean Metric used to describe the elapsed time from process start to process end. It can be measured for a single process step or for the entire process. It is the sum of Processing Times, Preparation Times, Waiting Times and Inspection Times. Breaking TPT down into these elements also helps identify how to improve TPT.
Determining Throughput Time is critical when analyzing business processes as it helps figure out where improvements can be made. It makes sense to build on Throughput Time if you plan to make your production more Lean, or if you must reduce Work in Progress (WIP). Often it’s helpful to understand TPT when it comes to reducing Lead Time and improving Service Level (OTIF).
WHY REDUCE THROUGHPUT TIME?
- Reduction in Bound Capital – Cash out
- Reduction in WIP (Work in Process)
- It can lead to reducing Lead Time.
- It usually leads to reducing costs, however this is often difficult to measure as cost reductions result from eliminating waiting times, rework, inventory, and a generally higher productivity.
WHAT'S DRIVING THROUGHPUT TIME?
- Batch size
- Process wastes
- Production Planning
- Work in Process (WIP)
- Product mix
HOW TO MEASURE THROUGHPUT TIME?
- Visualize the process in scope, e.g. use Process Mapping
- Clearly define which actions start and end the process in scope
- Select one piece of material and measure the time it takes this material to go through the process from start to end