Available production time per day 7.5 hours/day Takt time = ———————————————— = ——————— = 0.5 hours/unit Customer demand per day 15 units/day
The usual period for calculating takt time is one day or one shift. The core concept of lean manufacturing is to arrange all processes in the production sequence in a smooth flow based on the rate of sales, i.e. the takt time. Mathematically, as the customer demand is changing, also the takt time is changing. Once the takt time is calculated for a determined period, it is fixed for that period. The working pace in that period is also fixed, that is, all parts during this period are produced in the same speed, for example every 30 minutes. This is typical and usual for final processes like assembly lines. Maintaining the same working pace is not a problem for processes driven with high technology. However, this represents a problem, when the processes require a large portion of human work. Humans are not able to keep the same working speed during the longer period as the machines can.