Takt time

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"Takt" redirects here. For the chamber ensemble in Arab music, see Takht (music). For other uses of "takht", see Takht.

Takt time, derived from the German word Taktzeit, translated best as meter, sets the pace for industrial manufacturing lines so that production cycle times can be matched to customer demand rate. For example, in automobile manufacturing, cars are assembled on a line, at a certain cycle time, ideally being moved on to the next station within the takt time so as to neither over or under produce. The cycle time to complete work on each station is often less than the takt time in order to ensure that the customer is never short of product. Although theoretically you want to match cycle time to takt time to avoid building inventories and over-sizing equipment, the reality is that demand is dynamic and never precisely known and also process disruptions such as unplanned downtime can occur. Thus, in practice, it is generally understood that cycle time needs to be slightly less than takt time.

Definition[edit]

Assuming a product is made one unit at a time at a constant rate during the net available work time, the takt time is the amount of time that must elapse between two consecutive unit completions in order to meet the demand.

Takt time can be first determined with the formula:

T = \frac{T_{a}}{D}

Where
T   = Takt time, e.g. [work time between two consecutive units]
Ta = Net time available to work, e.g. [work time per period]
D = Demand (customer demand), e.g. [units required per period]

Net available time is the amount of time available for work to be done. This excludes break times and any expected stoppage time (for example scheduled maintenance, team briefings, etc.).

Example:
If there are a total of 8 hours (or 480 minutes) in a shift (gross time) less 30 minutes lunch, 30 minutes for breaks (2 × 15 mins), 10 minutes for a team briefing and 10 minutes for basic maintenance checks, then the net Available Time to Work = 480 - 30 - 30 - 10 - 10 = 400 minutes.

If customer demand was, say, 400 units a day and one shift was being run, then the line would be required to output at the rate of a minimum of one part per minute in order to be able to keep up with customer demand.

In reality, over the longer term people and machines cannot maintain 100% efficiency and there may also be stoppages for other reasons. Allowances should be made for these instances and thus the line will be set up to run at a faster rate to account for this.

Also, takt time may be adjusted according to requirements within the company. For example, if one department delivers parts to several manufacturing lines, it often makes sense to use similar takt times on all lines to smooth out flow from the preceding station. Customer demand can still be met by adjusting daily working time, reducing down times on machines and so on.

Some of the early literature uses cycle time for takt time.

Implementation[edit]

Takt time is calculated on virtually every task in a business environment. It is used in manufacturing (casting of parts, drilling holes or preparing a workplace for another task), control tasks (testing of parts or adjusting machinery) or in administration (answering standard inquiries or call center operation). It is, however, most common in production lines that move a product along a line of stations that each perform a set of predefined tasks.

Once a takt system is implemented there are a number of benefits:

Downsides of takt time organization include:

References[edit]

  1. ^ Laraia, Anthony C.; Patricia E. Moody, Robert W. Hall (1999). The Kaizen Blitz: accelerating breakthroughs in productivity and performance. New York: John Wiley and Sons. ISBN 978-0-471-24648-0.  [page needed]

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