Takt time

Takt time = Customer demand / working hours, it means the maximum of time per piece in output which can achieve the customer demand.

Cycle time = the total process time in sum of all work station.

In process design, we are following the thinking of takt time to work on, but it is hard to achieve perfectly. When we received customer demand, usually, it is an annual usage, we would calculate the takt time accordingly. Then, we will select a manufacturing mode to fit with the takt time. Nowaday, most of the process engineers always jump to the select the mode according to their experiance without the supporting from takt time. Actually, the engineers can intuit to know what kind of manufacturing mode is suitable according to the annual usage quantity. Whatever, I suggest we should calculate the takt first, and I called this with "customer takt time".

For selecting manufacturing mode, I have some explanation here. No matter what kind of manufacturing mode you selected, the consumption of process time is located in a specified range. In other words, you can not adjust the process time in a big gap. We was challenged if the takt time is 100% ramp up or 50% drop. If we face the cases stated in unstable of customer demand, what should we do? Can we adjust the process time as the takt time changed? Negative, but we can choose another manufacturing mode.

Afterward, according to the selected mode, we can calculate the cycle time according to the mode. According to what kind of manufacturing mode, you can adjust the configuration of the process flow to have a cycle time and process time for every stations. With that numbers, we can fine tune the process flow to meet with the takt time. I called this with "process takt time". Compare these two takt time, "customer takt time" and "process takt time", to see the process can achieve with customer requirement or not.

Finally, all the production schedule must be arranged according to the balanced takt time. It is talking about the execution force to sustian the process flow.

Another question we always have, how about if there were many different products produced in one production cell? For this case, we should do the same in most of the stages above, but we have to balance all the takt time together. Let's say if we have three products are producing in a cell, we need to adjust the sum of takt time of three products together. make sure that there is no exceed working time left for the scheduling. It looks difficult, but just try for that. We always found that it is not difficult as we though.