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TAKT Time—Stopwatch or Calculator?
By Ron Minke

With all of the discussion about lean and process improvement, TAKT time is a buzz word that is frequently bandied about. What really is TAKT time, how is it determined and why should I really care?

The lean definition of TAKT time is “the available work time divided by the average demand”.(1) TAKT time is therefore an integration of customer demand and available resource time. TAKT time is not measured with your stopwatch, it is a calculation and is expressed as “seconds (time) per piece (unit).

Elements of available time should include all time available to potentially make parts. Items like breaks, lunch, cleanup and planned meetings should be subtracted from the total time to arrive at the available time. Other items such as changeover time and an allowance for OEE (Overall Equipment Effectiveness) should remain in the available time calculation so that these wastes remain as focus items.

TAKT time is definitely not the cycle time of a machine or a process. Should a machine or processes cycle time exceed the TAKT time, you have just identified a constraint, a situation requiring parallel processes, overtime or further study. Perhaps some of the work for the constrained process can be done on another piece of equipment, in another manner or maybe even eliminated.

Suppose that your TAKT time calculation comes up very close to the “Rule of 50”, (50 second per piece TAKT time)(4), and one of your process steps has a 40 second cycle time. The result would be that the 40 second process should be idle for 10 of the 50 seconds. That’s right, your operator should not start the next part until the TAKT time has fully expired. This prevents the waste of overproduction and unnecessary WIP. After all, you only get paid for the parts that ship out, not the ones in inventory.

Wow, I can’t believe that I should be expected to accept this 20% inefficiency ((50-40)/50). Perhaps you don’t have to. If you can rebalance the work loads that would be great but it is not always possible to do. Slowing down to work at the TAKT time will achieve synchronization and may actually produce a desirable reduction in lead time. It is the output of the entire operation that is important, not the micro efficiencies of the individual steps.

“The New Lean Toolbox”, John Bicheno, January 2004, Picsie Books
“Getting Lean”, Jerry Feingold, WCM Associates, 2002
“Lean Thinking”, Womack and Jones, 2003, FreePress
“Know your takt time”, John Miller, Gemba Research, 2002