Lean - Planification using EPE concept (Each Parts Each)

[AdamP]

Adam,

For the benefit of our Members, could you start a discussion about this topic here?

Stijloor, Forum Moderator.

Sure - Not sure if this becomes a new thread or if we continue this one. But I think what can benefit folks here most will be a mix of the formulas for determining the interval and maybe more importantly, if we can get members here to illustrate practical examples of their application.

The topic here is production smoothing for mixed model flow and specifically Heijunka and EPEI as approaches to that.

Some external resources have been noted already within this thread and I also searched here on 'Heijunka', finding some responses from a few years ago. One response to a request for benchmark companies on Heijunka refers to a consultant group, Duggan Associates (www.dugganinc.com)
which advocates the use of EPEI within their Lean teaching. A part of my current company works with Duggan and they have had good success implementing EPEI as a part of their implementation.

Does anyone here have practical examples of how they've used Heijunka and or EPEI for production smoothing?

 

[terhex]

Hi,

Every part every interval (EPEI) is basically running all part numbers (Every part) in given span of time. Traditionally we run on monthly interval. Inventory required to meet monthly interval is 4 times that of weekly interval. So if you want to bring down inventory it can be only through reducing the intervals.

So find out how much interval is possible with current state / capacity.
It can be done by excess capacity available in current state to do extra changeover.
If excess capacity accomodates fornightly (to say). Now split monthly plan into two equal fornightly plan consisting of all part numbers & schedule the part numbers in certain sequence in first fornight & repeat the same sequence & quantity in second fornight. By doing this way, 1. Waste is halved (ie inventory in value stream comes down to half) 2. Variation is eliminated. (Production schedule is same fornight after fornight).

In future, try to take next 3 month demand & split it into 6 equal fornightly plan, & execute it.

If you carefully observe only hurdle for reducing interval is changeover time. Apply improvement techniques to reduce changeover time by 50%,viola now fornightly interval goes down to weekly.

To conclude Inventory is proportional to interval & interval is proportional to changeover time. Therefore inventory is proportional to changeover time

Of course other losses can also add to inventory, but those are unplanned losses that has to be eliminated. Only setup change & tool change are planned loss & acceptable.

Take care you have to involve supply chain, production scheduler, dispatch guy & customer promising team, production & process team before doing these changes.
More over only reason for EPEI reduction is inventory reduction. for that we need hard work & team work interms of equally split repeatable weekly schedule, setup time reduce to enable this weekly schedule & problem solving of unplanned losses.

If customer is taking material only once a month, then interval can be considered as monthly. Also if economic order quantity for particular line is 100, dont split orders less than 100, rather schedule this order once a month & other possible part numbers to fornigtly & weekly.

Now after reading this you may be totally confused or understood why oee has to 85%, changeover has to be less than 10 minutes & secret behind reducing inventory.