“What?”
That’s usually the first question the uninitiated ask. “Are you saying tack time?” is the next. Those of you using Lean know the answer, but let me just refresh.
Takt is a German word meaning pace or tempo, as in the pace of a piece of music. In an orchestra, pace is usually governed by the speed of the conductor’s baton.
In Manufacturing, Takt Time is the pace at which your process needs to operate in order to meet customer demand. It is calculated by dividing Available Time by the Customer Demand.
Available Time is the worker’s scheduled time, say 7:00 AM to 3:30 PM (8.5 hours), less any breaks, lunch, meetings, cleanup time, etc. So, in the following example, Available Time is ___________?
Scheduled time: 8.5 hours = 510 minutes
Breaks 2 x 15 = - 30 minutes
Meetings - 0 minutes
Lunch - 30 minutes
Cleanup - 12 minutes
- 72 minutes
Available time = 510 - 72 = 438 minutes
Demand = 40 pieces per day
“Cool. So what?”
Takt Time (TT) tells us how long we have to build one part. If we exceed Takt time even once during the building of today’s 40 pieces (but stay on pace for the rest), we will not get all 40 built. We’d have to work some overtime. A goal of Lean is to work NO OVERTIME; so, we always need to work within Takt Time.
“No Problem,” you say. “I’ll give my workers 40 minutes to get it done and we’ll never exceed Takt Time.”
That’s no good either. You’ll either rush workers and get poor quality; or, you will need to assign more workers. Neither is acceptable.
Note — and this is huge — we don’t care how long it currently takes your workers to build one of these parts. That time, by the way, is called Cycle Time (CT): the time to build one good part.
Ultimately, our objective is to make CT less than or equal to TT. In order to achieve that, we typically use a Standard Work Kaizen event, but that’s for another post.
Summarizing, you’ve learned about Available Time, Takt Time and how to calculate both.
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