Questions from the Field #2: Lean Engineering

Second in the series of questions on implementing Lean in engineering…
2) How do we run to a variable Takt time, and are there other ways to pace or level load work flow?
If Takt time varies due to variation in demand, there are several things you can do to maintain an even pace and even work flow.
First, running to a variable Takt time is not something unique to engineering processes. Any time demand fluctuates against a relatively fixed net available time to get the work done, Takt will vary (Takt = Net Available Time / Demand). Balancing the workload and to Takt time, and having several different work balance scenarios depending on the Takt time (longer or shorter) and the cycle time (longer or shorter) is all a basic part of creating flow in Lean. There’s no need to go in to that in depth here.
Second, you can set an artificial Takt time that is faster than actual demand. Get the work done quicker and move onto something else. If something takes less time or has a long Takt time, complete the work and move on. In order to keep this person productive, cross training upstream and downstream is essential.
Third, follow the rule “when you can’t flow, pull”. Flowing work one-piece at a time based on downstream pull paced by Takt is the ideal for TPS. In the early stages, flowing to Takt will be difficult. Flowing at all is an accomplishment for most engineering organizations new to Lean. Connect the processes so that the customer (downstream process) can pull the work when they have time available. This will begin to set the workflow in motion while you figure out the Takt.