Distribution centre - investment check

Background

Ackermann runs a distribution centre (WVZ) at its Gummersbach-Derschlag site. This consists of a high-bay warehouse for pallets (3 aisles) and crates (2 aisles). Incoming goods and transfer with production take place on one side of the warehouse, while the other side is used for outgoing goods with the order picking area. The existing order picking area, especially its pallet conveying technology, has become a bottleneck due to continuous change in the customers' ordering behaviour. Although the total transfer volume has not changed, there are far more, but smaller, orders. This increases the time and effort required for order picking. Restructuring of the order picking zone was drawn up to overcome this problem; this solution also provided for the investment of 2.5 mln. DM in handling and conveying technology. The new facility was supposed to enable an approximately 50% increase in efficiency compared to the solution to date.

Task

The planned new handling and conveying technology was to be checked with respect to its performance.

Implementation

Ackermann provided the required order mix data and therefore utilisation of the order picking zone and the high-bay warehouse. In addition, it provided the technical specifications for the handling and conveying technology, e.g. lengths of the conveyor sections, speeds, stoppage times and duration of the rotations. A model was created from all this information. On the one hand it generated order picking orders in accordance with the order mix requirements and simulated their flow through the order-picking zone. On the other hand, it simulated the handling and conveying technology, both for pallets and for crates, which supplied the order-picking areas and therefore the orders. The model essentially consists of four so-called networks in which the order logic and the handling and conveying technology are reproduced.

Order-picking from crates is reproduced and displayed in the "KastenKommi" network.

Figure 1: "KastenKommi" network

The "KastenTransport" network simulates the handling and conveying technology for transporting crates prior to order picking, from the crate order picking areas to the pallet order picking areas. As a result, deliveries which have to be serviced from the crate storage and the pallet storage are merged.

Figure 2: "KastenTransport" network

Order-picking from pallets is simulated by the "PalettenKommi" network.

Figure 3: "PalettenKommi" network

The main network connects the three named networks with respect to the order flow.

Figure 4: Main network

The model created was used to perform and evaluate simulations.

Results

Use of the simulation model made it obvious that the rotation of the pallets created a bottleneck, which limited the increase in efficiency to approximately 15% increased performance. However, through unrealistic acceleration of the rotation it was also possible to show that the aisle stacker limited the increase in efficiency to 20%.

Conclusion

A bad investment was prevented by spending 1% of the planned investment volume.