Case study

Productive Inventory Picking – How to achieve it

May 12, 2022 | Pallet Racking, Shelving

Probably the most crucial aspect of your entire operation, inventory picking will have a direct impact on customer satisfactory levels. Being the initial stage of the order fulfilment process, accuracy and speed is necessary to ensure the subsequent elements of the process remain faultless.

What is inventory picking?

Inventory picking is the labour orientated procedure during which requested products are located and picked before being prepared for shipping and this has become a customary process in retailing since the magnification of ecommerce.

The importance of optimal picking

In effect, inventory picking is an essential step towards customer satisfaction. When placing an order, customers expect a timely delivery of the right product and ensuring this relies heavily on an efficient picking process. When it comes to profitability, customers have great influential power because repeat business and referral markets all depend on how the customer feels about the service provided. For every customer whose experience has been positive, the chance of retention has increased and the opportunity to build customer loyalty opens up, which in turn will enhance profitability. If, however the customer received the wrong product or delivery is late, the chance of a repeat purchase becomes very slim and new prospects are likely to be advised by the customer of the ‘negative experience’, which can then hinder profitability.

Types of picking

The methodology of picking will vary from operation to operation depending on size, labour resources, SKU variety and turnover. Here are a few common picking strategies:

Individual picking

As and when an order is made, the individual items or SKUs are picked accordingly. This method, also known as ‘discrete picking’ is as simple, and straight forward as it sounds, although it can only work effectively in smaller operations with short travel distances and little variations in inventory.

Individual picking is suited to operations managing large bulky items or low order volumes. It is a low cost and uncomplicated process and given the extensive travelling times of the picker, this method would be too slow for fast moving operations.

Individual Picking Flow Diagram

Multi Order Picking

Sometimes known as ‘batch picking’, multi order picking involves the use of a combined list of various orders that require items from the same SKU and the items are picked in the same run.

Multi order picking is ideal if high order volumes of the same SKU’s is frequent because multiple orders can be fulfilled at the same time, simplifying the fulfilment of numerous orders in one journey and reducing travel time.

Multiple Order Picking Flow Diagram

Pick and pass

Often referred to as ‘zone picking’, pick and pass allows items to be picked from zones assigned to individual pickers as the order cart moves from zone to zone, ensuring directional flow and reduced congestion.

Pick and pass is ideal for high order volumes and although the process is speedy and travel time is minimised, multiple pickers are required to ensure each zone is covered resulting in higher labour costs.

Pick and Pass Flow Diagram

Pick and Merge

The same as pick and pass, however each zone can be picked from at the same time, increasing speed further

Pick and Merge Flow Diagram

The role of storage structures and handling equipment

Providing support to the process in multiple ways, effective storage and handing is crucial to ensuring inventory is organised, accessible and visible. This helps to simplify the picking process whatever the inventory type, method and size of the operation. The ability to locate and pick items from the pick list with ease supports productivity and enhances customer satisfaction levels.

The key to an effective storage solution is through bespoke design because it ensures the right type of system is implemented while the individual space is maximised and the most optimal picking process is supported. So, what needs to be considered?

Inventory type

Inventory varies. Some inventory types are large and bulky whereas others are small and light. Some is palletised and is stored using a pallet racking system and others are stored individually for which the right shelving system is required. Some goods are perishable and others might be fragile or highly valuable. The right solution for your operation will depend on these types of characteristics as well as volume, speed and process strategy. Another factor to consider is available space and how it can be maximised to support your operation and increase profitability.

How to create an energetic picking process

If order volume is on the rise, you’ll be looking for new ways for your operation to keep up. Dynamic storage systems support inventory flow with movement and energy for the purpose of simplified picking. Available in many formats, dynamic structures consist of deep lane storage and has the ability to maintain orderly and sequenced picking with minimal human interaction. Once placed into the structure, inventory movement can begin and this is assisted by gravity, radio control or manual control, depending on the system implemented:

Gravity assisted movement – These structures have a slight tilt to the lane and the inventory is able to glide along the rollers fitted the lane floor. The pallets or goods move towards the picking face on the opposite side to where they were placed to enable fast, effective picking. Pallet live racking, carton live shelving and push back racking use the power of gravity to move goods and because goods enter the system from one side and leave on the opposite side, they work using the First-in First-out (FIFO) method which means stock rotation is automatic.

Carton live dynamic system


Radio Controlled Movement – Moving pallets within the deep lane structure using a radio-controlled shuttle to transport them. This fully automated system is called the shuttle racking system where pickers work outside the structure purely to collect the pallets sitting on the mouth of the structure. The shuttle does all the transportation work which reduces the need for manual labour. The FIFO method can be adopted by using entry and exit sides which run parallel to each other, however more storage can be gained if stock rotation is not a priority. The number of shuttles required will depend on the speed of your operation as a single shuttle does need time to travel.

Manual movement – Best suited to low turnover inventory, mobile racking and mobile shelving store goods in a tightly compact configuration. The enclosed structures can be opened up using a turning wheel to create an access aisle, as and when needed. For infrequent picking, these solutions are true space savers and are an ideal way of keeping high value or fragile goods secure.

Picking at height

Yes, height space can be used to optimise your picking processes because as it is there, why not use it? Consisting of tall units of long span shelving with upper-level walkways and a staircase for access, a multi-tier picking system is structured to provide more productivity within the same surface area and can seriously enhance space usage.  Goods lifts can be fitted to transport loaded pallets, trolleys or carts between floors and a chute can be used to send individual items to the lower level at speed.

Similarly, tall racking can be implemented with narrowed aisles in order to maximise height and floor space combined. This is known as VNA racking and will require very slim fork lift trucks to navigate the aisles and pick at height. The speed of these trucks can be limited when navigating beyond the racks;however, picking speed can be enhanced through pick and deposit stations (P&Ds). These are drop off points at the end of the rack where the slim line truck can leave the pallets to allow the fast-moving counterbalance truck to pick them up and transport them to the shipping area.

Cantilevered P&Ds

The contribution of static storage solutions

Static pallet racking and shelving systems may not move inventory but it can be a vital support to the overall process and for operations looking for a simple solution with direct access and high visibility, static solutions are ideal.

When used in silo, a static pallet racking system such as wide aisle racking allows pickers access to every pallet or item with all stock visible. The aisle between the racks has a generous width to allow the FLT to manoeuvre with ease and the racking provides suitable storage for a wide range of products and can store multiple product types at the same time. The system is highly adjustable in terms of beam positioning or decking type in order to support your needs as they change. Storage capacity can be increased further by placing two rows back-to-back which reduces aisle numbers to increased pallet location numbers.

Drive-in Drive-through is another static pallet racking solution which offers deep lane storage with a distinct configuration. The structure is made up of numerous consecutive lanes in which the FLT can enter to pick a pallet before reversing back out. The drive-in configuration is entered by the FLT from one direction and works on the First-in Last-out (FILO) basis whereas the drive-though offers entry from both sides and operates on the FIFO method. Either way, the drive-in drive-through solution adds speed, simplicity and enhances space utilisation.

Drive-in Racking System

An optimal layout for optimal picking

Even the most effective structures and equipment are suddenly ineffective if implemented without considering layout. An optimal warehouse layout reduces travel distances and eliminates confusion which can hinder the process. Consider directional flow; your aim should be to ensure inventory flows in one direction from entering the facility to leaving the facility. This approach can be adopted through orderly departmental areas which are located in accordance to the process. This saves pickers and other operatives from traveling in multiple directions and causing congestions as they complete their tasks and instead, they follow a simple format. Inventory directional flow is instigated by the shape of the warehouse and the location of the goods-in and goods-out openings as the diagram below illustrates:

Diagrams illustrating the L I and U shaped flow layout

Find out more during a free site survey

For further advice and to discuss your needs in person with one of our expert technical designers, contact WSL today on 0113 2045350 or email and discover how to optimise your picking process with a solution that suites your operation, facilities and budget whilst ensuring warehouse safety.

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