EPEI (Every Product Every Interval)
Personalize This
Get insights for your role
EPEI measures how frequently a process can produce every product in its mix, indicating production flexibility and responsiveness.
Definition
EPEI (Every Product Every Interval) measures how often a process can produce its complete product mix. If a line can produce every SKU once per week, EPEI is one week. If it can produce every SKU every day, EPEI is one day. Shorter EPEI means greater flexibility and responsiveness—customers wait less, finished goods inventory is lower, and demand changes are absorbed faster. EPEI is primarily determined by changeover time and frequency; reducing changeover time through SMED enables more frequent changeovers and shorter EPEI.
Examples
A packaging line runs 20 SKUs. With 2-hour changeovers, they batch large quantities and achieve EPEI of two weeks—each SKU runs once per two weeks. After SMED reduced changeover to 15 minutes, they run smaller batches more frequently, achieving EPEI of one day. Finished goods inventory dropped 80%.
Key Points
- EPEI = total changeover time / available changeover time per interval
- Shorter EPEI means lower inventory and faster response
- SMED (changeover reduction) is the primary lever for improving EPEI
- Not all products need the same frequency—A items may run daily while C items run weekly
Common Misconceptions
EPEI must be the same for all products. High-volume A items may need daily or more frequent production while low-volume C items may only need weekly or monthly runs. EPEI targets should align with demand patterns and customer expectations.
Short EPEI always justifies the investment. Changeover reduction has costs. If customers are satisfied with current lead times and inventory costs are manageable, extremely short EPEI may not provide sufficient return.