David Krause16.1 Why the shift model changes the labor rate
The collective wage is the same in every shift. What differs are the premiums — and they are subject to social security, so they act twice.
| Component | single-shift | two-shift ★ | three-shift |
|---|---|---|---|
| Base wage | 22.00 | 22.00 | 22.00 |
| Early/late shift premium | — | +1.70 | +1.70 |
| Night shift premium (25 %) | — | — | +5.50 |
| Shift bonus | — | +1.20 | +1.80 |
| Ø gross wage | 22.00 | 23.45 | 25.33 |
| Employer social security (21.1 %) | +4.64 | +4.95 | +5.34 |
| Holiday pay, special payment | +1.83 | +1.95 | +2.11 |
| DL hour rate | 28.47 | 30.35 | 32.78 |
| vs. single-shift | 100 % | +6.6 % | +15.1 % |
Three-shift makes labor 15 percent more expensive — but lowers the machine hour rate from €46.37 to €33.90/MH, i.e. by 27 percent (Chapter 7.2). For machine-intensive parts the second effect clearly dominates. For labor-intensive manual workstations the relationship reverses. Which model is cheaper is therefore decided by the ratio of machine to labor share in the product — not by gut feeling.
16.2 Four shift models in labor cost comparison
Starting point: base wage of a production worker €22.00/h gross (metal collective agreement, Saxony), employer social security 21.1 %, shift and night premiums per framework agreement. The DL hour rate rises noticeably with the shift model.
| Labor component | single-shift | two-shift ★ | three-shift |
|---|---|---|---|
| Base wage (collective) | €22.00/h | €22.00/h | €22.00/h |
| Early/late shift premium | — | ~€0.85/h | €1.70/h |
| Night shift premium (25 %) | — | — | €5.50/h |
| Shift bonus | — | €1.20/h | €1.80/h |
| Employer social security (21.1 %) | €4.64/h | €4.95/h | €5.34/h |
| Holiday / annual special payment | €1.83/h | €1.95/h | €2.11/h |
| → total DL hour rate | €28.47/h | €30.35/h | €32.78/h |
Between single-shift and three-shift lie €4.31/h — about a 15 % labor cost difference. Whoever costs all orders with the same DL rate although they run in different shifts distorts every post-calculation. The two-shift rate (€30.35/h) is this book's reference value.
16.3 Multi-machine operation
If a worker operates two or three machines at once, their wage spreads over several orders. The DL hour rate per machine falls accordingly — the machine hour rate stays unchanged.
Two-shift, two machines: 30.35 / 2 = €15.18/h
Two-shift, three machines: 30.35 / 3 = €10.12/h
Multi-machine operation only works with sufficiently long spindle times. If the worker becomes the bottleneck — because two machines need a tool change at the same time — waiting times arise that appear as availability loss in the OEE. The saved labor then reappears as a higher machine hour rate. Whoever increases the number of machines operated must keep an eye on the OEE.
