1. EPEI – Every Part Every Interval
Overview of the purpose and application of the tool
Tiago Lopes, Industrial Engineer/Executive MBA, May 2014

2. What is the EPEI ?
EPEI stands for Every Part Every Interval. Normally the interval is then replaced by the time period relative to the calculation – day(s), week.
EPEI is the lot size expressed in time.
It is an indicator to follow the number of times a part is produced. The primary reason for implementing quick changeover is to be able to reduce the lot size...

3. “Mind map” on interdependencies of cost
These issues are being addressed directly (but indirectly many others are impacted )

4. The mechanics…(1/2)
Identify the equipment (line, machine, etc.) to apply the study
Identify all the parts to be produced on the equipment (e.g. Part A; Part B; Part C)
Identify the production time and setup time of the parts (e.g. Total time A = Production time A + Setup time A, etc.)
Add all the times and compare to total available time for the equipment. This is the “minimum” required to produce the customer needs
The difference can be used to “break” the required production into smaller lots. Any improvement to the setups will allow to divide production into more/smaller lots

5. The mechanics…(2/2) Start identifying times (EPEI = 1 per interval)B C
Start identifying times (EPEI = 1 per interval)
Reduce lot (increase EPEI), «breaking» lot into two, repeating setup (EPEI = 2/i)
Reduce lot even further with reduced setup (EPEI = 3/i)
Free time
Total available time

6. Conclusions
The goal is to have a lower EPEI - why would we want this? If we have a smaller EPEI, we can have less inventory and shorter lead times. If your EPEI is one week, you will need to have about 5 times more inventory (and lead time) than if you had an EPEI of 1 day.
But this needs to be balanced with the costs of setup (which we all agree need to tend to zero)...
… and that produced batches can be evacuated – meaning that batches are not going to «sit» in the warehouse

7. Who am I? I’m an Industrial Engineer and exec. MBA Experienced in
Management: Plant Management, Business management, Project Management, VA/VE and other special projects
Operations: Supply chain, Industrial footpath & Green field operations, Lean process installation & Ergonomics, Lean 6 Sigma continuous improvement
Finance: P&L, Cost calculation, Price target strategies
International footpath,
Passionate for sci-fi and strategy