November 12, 2009
Lean manufacturing is one of those rare production crazes that actually works. People that have never heard of it might immediately think it implies reducing the size of the workforce. This is simply not the case.
Lean manufacturing means to produce with the goal of zero waste. So the question is, "What is waste?" Waste is finished goods inventory sitting in the warehouse not doing anything. Waste is a downstream work center waiting while upstream work centers are falling behind. Waste is time spent looking for tools because the workspace is a mess.
If it is not adding value, it is waste.
The shift work structure used in a Lean Manufacturing environment is extremely important. It would be a wild coincidence if every work center needed exactly the same amount of coverage every day.
In actual practice, companies try to do just that. They put everyone on the same schedule and then hope that the workload balances out. When it doesn't, waste is created either by high overtime, high inventories or idle work centers.
Lean manufacturing works. Make sure your shift schedule works as well.