*** Welcome to piglix ***

Takt time


Takt time is the average time between the start of production of one unit and the start of production of the next unit, when these production starts are set to match the rate of customer demand. For example, if a customer wants 10 units per week, then, given a 40-hour work week and steady flow through the production line, the average time between production starts should be 4 hours, yielding 10 units produced per week. Note, a common misconception is that takt time is related to the time it takes to actually make the product. In the previous example, whether it takes 4 minutes or 4 years to produce the product, the takt time should be 4 hours (of course, the time it takes to produce the product will impact the magnitude of the number of units actually in production at any point in time).

Takt time is a borrowing of the Japanese word takutotaimu (タクトタイム), which in turn was borrowed from the German word Taktzeit, meaning clock interval. The word was likely introduced to Japan by German engineers in the 1930s.

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:

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

In reality, people and machines cannot maintain 100% efficiency and there will 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.


...
Wikipedia

...