What is parallel picking?
Parallel picking in logistics means that a sales order is first divided up into several parallel partial orders by the warehouse management system. Afterwards, the partial orders are picked in parallel by several pickers in the storage areas (picking zones) and are later merged into one order again.
Details and simple explanation of parallel processing
In the merchandise management system, the order-oriented entry is made first. In order to optimize the total picking time (picking performance), the sales order is divided in the Warehouse Management System into several storage areas in parallel and prepared as a partial order.
Each order is then picked in the picking process in parallel in separate picking areas by several pickers in totes or shipping cartons (according to the picking list). For the picker, the parallel partial order is no different from a normal order.
Each item of the order is picked with the picking method used (e.g. picking with Pick-to-Light, Voice Picking, Pick-by-Point®, etc.). The goods are removed from the storage location as normal. To optimize the picking time in the process, the picking time, dead time and travel time should be as short as possible.
Once all the goods have been completely picked, the individual picking orders must be reassembled in the method. Sorters or conveyor systems are often used for this purpose to save distances.
Start of the parallel partial orders
In order to achieve an optimal start of the parallel partial orders, the material flow system must first calculate the optimal start time of the individual orders. Here, the order lead times in particular must be taken into account. The aim of the optimization is that all parallel partial orders are completed as simultaneously as possible and thus no waiting times occur.
Merging the parallel partial orders
Once parallel picking in the warehouse has been completed, the individual orders are combined in an order-oriented manner. The distribution time should be as short as possible for the picker. The following methods can be used for this:
- Picking methods for pallet distribution (Put-to-Point)
- Accumulation of goods with a flow rack (optimal picking method Put-to-Light)
- Manual sorting of goods with MDE (very outdated and slow)
Once all items have been brought together in an order-oriented manner, shipping can take place. The selection of the optimal picking method is not covered in this article.
Advantages of parallel picking
Depending on the structure of the supporting picking systems, parallel picking has the following advantages:
- High performance through order-oriented picking in separate storage zones (important: correct ABC analysis).
- Short base times due to distribution of tasks to several pickers.
- Optimal use of picking methods, such as Pick-to-Light, Voice Picking, Pick-by-Point®, etc. for picking partial orders.
Disadvantages of parallel picking
The disadvantages are defined as follows:
- This procedure is only useful for large warehouses with many storage zones (picking zones) and many articles.
- Due to the warehouse structure, it is not always possible to distribute the sales orders among the sub-orders in an optimal way.
- High technical effort in merging the parallel orders.
Conclusion
Parallel order picking is suitable for large warehouses with many storage zones and high automation (Pick-to-Light, Voice Picking, conveyor technology, sorter systems) for fast picking. Several pickers can process a customer order at the same time. The merging of the partial orders is complex and has to be controlled by the material flow system together with the picking.
Comparable picking processes
For comparison, you can also read about the other picking methods:
Single-level picking
Two-level picking Two-level picking
Multi-level picking
Serial picking
Serial-oriented picking