Order picking is a crucial operation in an order fulfilment procedure. It accounts for 55% of operations costs, so it is arguably the most significant part of the fulfilment. Since it accounts for more than half of the labour cost, picking should be quick and accurate.
That’s where these various picking methods come into the picture. The best picking method for your operations will depend on factors such as:
- Warehouse size
- Daily order volume
- Priority (Is it raising accuracy? Shortening your fulfilment times? Or, do you want to save time and money on training and technology investment?)
Let’s take a look at the different picking methods that are used today, and see which one might be the best to implement in your order-picking process.
5 Common Order Picking Methods
There are 5 common picking methods used in the industry. These methods can be conducted using paper or technology, whichever way you prefer or can afford. The recommended warehouse size and order volume for each picking method scale up as we go down this list.
Single Order Picking
Single order picking (also known as Discrete picking) is a method that involves picking all items for a single order before moving on to the next one. Since it is one of the most classic methods, it can be easily done with paper and pen. In essence, all you have to do is go through the list of orders from top to bottom.
- Low-cost implementation and easy to teach.
- Reduces the risk of items from one order getting mixed up with items from another.
- Works well in smaller warehouses with less travel time between storage locations.
- Slow and inefficient when you have large daily order volumes.
- Increases the risk of employee injury due to unoptimised routing.
- Can become expensive in terms of labour costs as order volumes increase.
If you’re in a startup position for your ecommerce business, this would be the easiest method to start with.
Batch Order Picking
Batch order picking (also known as Multi-order picking) involves picking groups or ‘batches’ of orders based on product, not based on the orders themselves. So, you would pick multiple quantity of the same product that are required to fulfil multiple orders. The products are usually divided into each order after they have all been picked.
- Reduced travel time for the picker when fulfilling multiple orders of the same product.
- You can assign different pickers to different SKUs, making it even simple for them to execute their role better.
- Faster than the single order picking method.
This method is a common upgrade from single order picking. It works better if your product line has increased and order volume is starting to grow.
Cluster Order Picking
Cluster order picking is a method where you ‘cluster’ the orders into a group and pick all of the items in one go.
At first, it sounds similar to the earlier two picking methods. However, cluster order picking is not focused on similar factors. Pickers will simply pick all of the products from multiple orders in a single trip around the warehouse.
- Faster than the single order picking method.
- Possible with both pen-and-paper and technology.
- Can be adopted to work with automated picking equipment.
- Increased risk of items from different orders getting mixed up.
- More time travelling between storage locations if the route is not optimised.
- Not practical for large warehouses with many product locations and locations that require picking machines.
If you want to try this method, it is highly recommended that you use it with warehouse management software and trolleys with slots for each order. The software can calculate the most efficient route for you and the trolleys will prevent you from getting the orders mixed up. This is how we do it in KeepSpace 3PL too!
But, again, it is still manageable with paper and pen.
Wave Order Picking
Wave order picking is a method where orders that share a common factor are picked at a specified time of day. These picking intervals are called ‘waves’, hence the method’s naming.
The most practical examples of factors are customer location, order date, and required-by-date.
- Improves picking efficiency when scheduling waves according to factors that will most benefit the business.
- It can be combined with other picking methods.
- You can match picking times with when specific carriers come to collect, maximising the number of orders shipped per day.
- Difficult to process last-minute or urgent orders.
- Requires knowledge of complex data, such as the value of prioritising certain shipping carriers or customer types.
- It can create downtime when pickers are forced to wait for the person ahead of them.
Because this method involves some knowledge of your business data, it is further down on this list. It means you would need a few years of experience or past volume to base your picking choices.
Zone Order Picking
Zone order picking involves physically dividing the warehouse area into sections or ‘zones’, and each picker will be allocated to a single zone.
If an order has a product that is within a specific zone, that picker assigned to that zone will be responsible for picking and preparing it for fulfilment. This picking method is often combined with either Batch or Wave order picking to raise efficiency.
- Pickers become familiar with items in their zone, which improves efficiency and reduces picking errors.
- Travel time per picker is minimised while productivity is maximised.
- Can be combined with other picking methods.
- Doesn’t work well with smaller warehouses with a limited variety of products.
- Items are sometimes handled by multiple pickers, leaving more room for human error.
- Not very flexible; it always requires a scheduling period per shift and orders placed after the cut-off time must be held back until the next shift.
Now, which picking method should you use?
We’ve looked at the basic 5 methods of order picking. Now, let’s quickly look at each method based on some of the factors mentioned at the start of this blog.
- Single Picking – Small
- Batch Picking – Any size
- Cluster Picking – Small to Medium
- Wave Picking – Any size
- Zone Picking – Big
Daily order volume:
- Single Picking – Low
- Batch Picking – Any volume (better for limited product variety)
- Cluster Picking – Low to Average
- Wave Picking – Any volume
- Zone Picking – High (with a variety of products)
For priorities, you should reflect on what your ecommerce operations currently need to improve. Then, look at each picking method and see if you clear the recommended warehouse size and daily order volume. If you clear it and it seems to provide a solution to your problem, let’s try it out!
Otherwise, you can also try outsourcing your ecommerce store’s fulfilment to a 3PL (like KeepSpace!) 3PLs have plenty of experience handling various products on a daily basis. So, they will have a well-structured picking method that will help you scale up your operations.