Investment comparison
| Relative payback period | ΔTA | = | a. |
| Investment | I1 | = | Tsd € | |||
| Investment | I2 | = | Tsd € | |||
| Depreciation | A1 | = | €/h | |||
| Salary | L1 | = | €/h | |||
| Cycle time time ratio | CTb | = | ||||
| Depreciation | A2 | = | €/h | |||
| Salary | L2 | = | €/h | |||
| Number d. layers | nS | = | Stck. |
When comparing investments, two different manufacturing processes with different investment amounts and different manufacturing efficiency are compared in terms of economic viability (proof of economic viability). The question is examined after how many years the additional costs of the higher-value investment were compensated for by the efficiency improvements. This unit of time is called the relative payback period.
Better economic efficiency can arise when one process is compared to the other process
- more time efficient
- more material efficient or
- is more energy efficient
Different types of presses or tools cause different press occupancy times. The cycle time is the total time required for set-up, production and preparation of the stamped parts.
Often attempts are made to carry out several work steps in one tool in the form of an overall composite tool. The multiple effect required for this is preferably achieved with springs in the tool. If the press has several rams or a table drawing cushion, the required multiple action is carried out by the press.
Overall composite tools have a significantly reduced cycle time and can be operated very economically. When comparing processes, the cycle time ratio can be used to find out at what point in time the additional costs of an investment have been made up for by more efficient production. The reciprocal of the cycle time ratio is the productivity ratio Pr.