Production Scheduling – 7 Lean Principles
The other day I came across an early version of the Lean Enterprise Institute’s “Learning to See” workshop from 1999. The workshop listed seven guidelines for the design of a future state value stream. These guidelines remain relevant today.
- Produce to your takt time.
- Develop continuous flow wherever possible.
- Use supermarkets to control production where continuous flow does not extend upstream.
- Send the customer schedule to only one production process.
- Level the production mix by distributing the production of different products evenly over time at the pacemaker process.
- Level the production volume by releasing and withdrawing small, consistent increments of work at the pacemaker.
- Develop the ability to make “every part every day” (then every shift, then every hour, or pallet or pitch) upstream of the pacemaker process.
You don’t hear about these guidelines very much these days. The lean manufacturing talking points have shifted away from “tools” toward an emphasis on “culture”. I think that we miss many of the concrete bottom-line benefits of lean when we ignore these key principles. But that’s a discussion for another day…
Let’s talk about production scheduling!
Working with many complex manufacturers, I have found production scheduling to be a huge challenge. Some manufacturers use point solutions or customize to try to get their schedule to work smoothly. Other organizations have just given up on rigorous production scheduling and adopt a “launch and hope” approach. (It’s a bit hard to call it a strategy.) They count on the firefighting skills of their most senior workers to get product out the door.
However, when business volume is high enough, production scheduling must be automated and operations must be in control all of the time. Because they cannot afford to suffer a shop floor meltdown, these companies are continually exploring various operational excellence initiatives.
As we work with these high volume and high mix manufacturers, part of my job is to help design their future states. I specifically focus on their production scheduling. Our criteria to evaluate a future state design are those lean design guidelines – but applied to a high mix world.
This is the first of a seven-part series on production scheduling for lean manufacturing operations. Let’s define production scheduling as the process of preparing work for release to manufacturing to build. Every ERP system (including Microsoft Dynamics AX of course) supports at least some level of production scheduling. Mostly commonly, the ERP system will create production orders or work orders indicating what should be manufactured to meet demand. Demand can come from either actual customer orders or forecasted orders. Even in very lean operations, companies have some level of production scheduling.
The first rule for production scheduling is that work should not be scheduled if it can’t be completed. Both capacity and materials must be available. Releasing work without both capacity and materials is a guarantee that WIP will increase. And that will inevitably result financially in lowering profitability. We’ll start with building to takt time next.
Written By: Phil Coy