Batch picking

Batch picking is an organizational variants of order picking system. It can be explained as collecting in one picking tour the whole set of orders.

The pick instruction, while batch picking is considered, consists of combined demand determined by customer's orders. One of the most important objectives of implementing this system is to plan sequence of locations of storage keeping units (SKU) to be visited in the way which can reduce time of travel and minimize time of the whole picking process.

Batch picking usually requires possessing picking carts ready to pick from 4 to 12 different orders in one batch. This kind of process is efficient while it is related to pick small items with long distance between SKU's or high concentration of storage keeping units over a large area of warehouse they are stored in.

Classification of order picking systems

Fig.1. Batch picking process - example

Order picking systems can be divided into two groups:

1. Employing humans group
2. Using machines group

The first group of order picking system consist of 3 types of picking methods:

• Picker-to-parts - it is one of the most common method which requires from picker or vehicle operator getting to the location where SKU is and pick them. This is also the method where batch picking belongs.
• Put system - consist of two processes: retrieval of storage keeping units and distributing them over customers order.
• Parts-to-picker - in this method automated storage systems is used for bringing SKU to position of picker. The person responsible for picking goods is supposed to take as many items from unit as order requires and then send the rest of them for storage at the previous location.

The second group which is using machines for picking system consist of two types:

• Automated picking
• Picking robots

Batch-picking strategies

Among batch picking strategies Two main strategies can be distinguished:

1. Pick-then-sort batch picking strategy - The picker of stock keeping units picks all of requires units and after that he starts to sort and consolidate them in the area appointed (mainly in created in the warehouse packing and consolidating zone).
2. Sort-while-pick batch picking strategy - In this case sorting process takes place at the same time as picking. For sorting-while-picking strategy the person who is responsible for handling with process needs to have special order-pick cart which makes dividing storage keeping unites for each order separately possible.

Main advantages of batch picking

Among advantages we can distinguish some improvements mentioned below:

• First of all batch picking can reduce time of picking process. Average time which is needed for picking order is shorter because in one pick tour more than one order can be picked.
• Second advantage of batch picking is making amount of unnecessary empty kilometers which picker or operator of internal transport vehicle needed to make, reduced. It happens when sequence of locations and plan of route is created properl.
• Batch picking can have good influence on minimizing combination of some fixed and variable picking costs.
• The service level in the warehouse can be maximized thanks to implementation of batch picking.
• Supervising is easier when complementation of customer order is made at area selected especially for that process.
• Using batch picking makes labor cost reduced.
• Choosing this kind of picking system can improve efficiency and productivity of warehousing.
• Introducing batch picking can be the way to increase pick density.

Main disadvantages of picking process

Batch picking has also disadvantages which consist of:

• In the same time only one batch picking process can be proceeded. Otherwise pickers or internal transport vehicle operators can interrupt each other.
• The volume of batch picked is limited in one tour. The size of batch depends on picking process window time and maximum capacity of vehicle which was chose for the picking. The volume of batch which can be transported at once determines also the amount of orders which batch can contained.
• The risk of congestion is high.
• Batch picking requires in some variants providing sorting process after picking storage keeping units to consolidate customer order and making sure that it is complete. It means that batch picking require double handling of the process which can be done at once.
• Necessity of preparation area in the warehouse where sortation and consolidation process can be handled.
• During batch picking there is no order integrity until units are consolidated.
• Lots of errors can occurred when batch picking is done without software system which supports process.
• Necessity of accumulating some of customer orders till creating batches which consist of similar units is possible.

Examples of Batch picking

• Zone Picking: Zone picking is a common method of batch picking that involves breaking the warehouse into different zones. Each zone contains a specific type of product and a worker is assigned to pick from that zone. The worker picks all items for each order in their assigned zone, and then moves on to the next zone. This method is useful for order sizes that are small or large, and for warehouses that contain a wide variety of items.
• Wave Picking: Wave picking is a type of batch picking that involves grouping orders together. For example, orders are grouped by customer, product type, or order size. All of the items in the group are then picked together, and then the next group is picked. This method is useful for warehouses that have a large number of orders that need to be fulfilled quickly.
• Pick and Pass: Pick and pass is a method of batch picking that involves dividing a group of orders into smaller batches. Each batch is divided among a group of workers, and each worker is responsible for picking the items in their assigned batch. Once the batch is complete, it is passed on to the next worker, who is responsible for picking the remaining items in the batch. This method is useful for warehouses with a large number of orders that need to be picked quickly and accurately.

Other approaches related to Batch picking

Batch picking is an organizational variant of order picking system, which involves collecting in one picking tour the whole set of orders. There are several other approaches to order picking that are related to batch picking:

• Zone Picking: This approach divides the warehouse into different zones, and assigns a picker to each zone. The picker then collects all the items from their assigned zone and places them into the designated order containers.
• Cluster Picking: In this approach, orders are grouped together into clusters and assigned to a single picker, who can move quickly between the different orders to fulfill them.
• Wave Picking: This approach involves grouping orders together into waves, allowing multiple pickers to work on the same order at the same time.

In conclusion, batch picking is one approach to order picking, but there are other related approaches that can be used to optimize the order picking process.

Footnotes

Batch picking — recommended articles

Transloading — Tertiary packaging — Optimization of transport — Internal transport system — ABC method — Multimodal transport — Transit shipment — Break bulk cargo — Pull system

References

• De Koster, R., Le-Duc, T., and Roodbergen, K.J. (2007)Design and control of warehouse order picking: a literature review, "European Journal of Operational research", 182(2).
• Hong Soondo, Johnson Andrew, Peters Brett. (2012)Batch picking in narrow-aisle order picking systems with consideration for picker blocking,"European Journal of Operational Research", Volume 221, Issue 3, 16 September 2012, Pages 557-570.
• Ross D.F. (2015) Distribution Planning and Control: Managing in the Era of Supply Chain Management Springer, Chicago.
• Van den Berg J.P. (2007), Integral Warehouse Management, Management Outlook, Utrecht.
• Won J. (2004), Order batching and picking optimization in terms on supply chain management Iowa State University, Ames.

Author: Fryderyk Olchawa