Wednesday, March 28, 2018

Just In Time - JIT - Unlearning Old Beliefs

UNLEARNING OLD BELIEFS

Implementing JIT production in a traditional manufacturing plant represents a big change - in the culture of a company as well as in its operations. Established routines and rules become obsolete. Thus applying the JIT philosophy requires not only learning some "new" ways of thinking, but putting some of our time - honored and cherished beliefs and practices to rest. The following table briefly compare the JIT philosophy against conventional wisdom:

Item
Conventional Wisdom
JIT Philosophy
Inventory
An asset
A liability
Lot size
Select lot sizes to balance set up cost against holding costs as a general principle.
Immediate needs
only
Set up
Low priority since, it represents a small fraction of the total time.
Make them insignificant
Queues
Necessary Investment
Eliminate them.
Vendors
Adversaries
Co-makers
Quality
Tolerate some scrap
Zero defects
Equipment Maintenance
As required. But not critical because we have queues available.
Constant and Effective. Machine breakdowns must be minimal.
Lead times
The longer the better (Most supervisors and buyers want more lead time). Keep them at planned levels •.
Keep them short.
Worker Involvement
Management by edict. Measurement to monitor adherence to plan
Management by consensus. The vital ingredient of "ownership" is achieved.