Optimizing warehouse space and layout to maximize efficiency

There isn't a warehouse design that works best. The best design is one that completely satisfies the operating needs of the present while considering future expansion by being adaptable, flexible, and scalable. Designing for the future while constructing for the present is the goal.

Design is all about trade-offs, just like in many other warehouse processes. Speed, travel distances, space use, handling, accessibility, safety, risk, and cost are all factors.

According to a study by Cranfield University, storage normally takes up 52% of a warehouse's floor space, followed by pick-and-pack operations at 17%, receiving and dispatching at 16%, value-added services at 7%, and other uses including battery charging and empty pallet storage at 7%. Naturally, a lot will rely on the warehouse’s exact operations.

Storage space normally only takes up about 52% of an average warehouse floor space

Books are written about how to optimize warehouse space and design it in the most efficient way. Therefore, in this article, we focus on a couple of key points only. The first part of the article will focus on determining the right amount of space for two key areas within your warehouse: storage and inbound. The second section assumes you have a space and focusses on optimization of the layout in order to use the space in the most efficient way.

Section 1: Determining the right amount of space

Optimizing the inbound area

This area is one of the most crucial in the warehouse but is occasionally disregarded in favor of storage space. Ample room is required for this warehouse operation, both inside and outside the dock bays. A crowded dock area can cause delays in inbound and outbound, product loss or misplacement, improper dispatches, and item damage.

Here is a quick formula to figure out how much room is needed for inbound:

Space = ((number of trucks x hours to unload) x (number of pallets x space per pallet)) / time of shift in hours

We also need to leave room around the pallets for working and moving around. The kind of forklift or pallet truck used to unload and load the vehicles will decide this area. Depending on how much access to the pallet is needed (for example on all four sides), this might potentially more than double the amount of space needed for inbound.

Optimizing the storage area

Numerous variables must be taken into consideration when determining the amount of storage space required and the way goods need to be stored.

It is necessary to assess each good by creating a table listing its many attributes, and then choose a viable storage medium based on that.

After calculating the number of items stored per product line and converting them to pallet quantities, one can compute the total number of pallets required to store each product line. After this, one can create an overview indicating the number of pallet locations necessary and the height requirement for each location. The height of the pallet will likely vary depending on the nature of the product (for example weight, fragility). Products that are low in quantity might only require bin- or tote storage.

The method of storage needs to be determined next. One can read more about this topic in our previous article: (Four factors to reach optimal warehouse occupancy)

The goal is to avoid having to restock locations throughout the picking process, hence the locations must be adequately sized based on the quantity of objects picked per day. The number and size of pick locations will be determined by the number of available ground level locations and their volume.

Design is all about trade-offs, just like in many other warehouse processes.

Determining aisle width

Aisle width is a key factor in warehouse layout. This is the space between neighboring racks' pallets.

The forklift truck's turning radius and the size of the pallet being transported define the aisle width. Narrow aisle and turret trucks are an exception, as the width those trucks determine the width of the aisle. To guarantee speedy pallet put-away and retrieval, a safety clearance of 10cm per side (20cm total) of a normal pallet will need to be added.

The truck's entire width when moving along the stacking aisle is the second factor one needs to include when calculating the ideal aisle width.

In general, aisle width decisions must optimize productivity, space use, flexibility, safety, and equipment costs for the individual application. Other considerations include the depth of the pallet on the truck and whether two trucks must pass in the aisle.

Section 2: Determining the right layout

Overall warehouse layout

The size, shape, access, equipment type, and intended purpose of the operation will all have a significant impact on the warehouse plan. Although there is no "magic" warehouse layout, some operations are better suited to certain layouts.

The U-flow shape is frequently used in warehouse layouts.

Inbound and outbound being on the same side of the building ensures high dock use and makes cross docking easier. The products that move the fastest are those that are closest to the dispatch bay, ensuring little travel time and providing the chance to combine put-away and retrieval.

The sort of pick activities that take place in the warehouse will have a big impact on the design, with special locations dedicated for item picking and value added services, for instance on a mezzanine floor above the inbound and outbound area.

Picking layout


Using ABC analysis based on the frequency of picking particular goods is a simple way to start optimizing your warehouse pick layout (for more information on ABC analysis, see our previous article on optimizing your cycle count: How to get rid of yearly stocktakes by properly setting up cycle count).

The next stage is to reduce the distance a picker must go through the warehouse. The warehouse must consider the following factors when planning for optimal picking routes.

•     Each pick will follow the most efficient route specified in the pick instruction, starting closest to the inbound area.

•     Heavy objects are picked first.

•     When navigating the aisles, the picker should be able to select items from both sides. The picker can move from side to side as opposed to traveling up the length of the racking and down the other side. To enable this, one can number the aisles rather than the rows of racking.

To reduce travel, shortcuts are built between the racks. As an illustration, a break in a long stretch of racking allows the picker to travel faster while still allowing the storage of reserve goods above the path.

The picker finally arrives as close as possible to the outbound area. In case picking is not real-time, he might have to go back to the starting place to pick up a new assignment, which is not ideal.

Placement of the most popular goods

To prevent crowding at the pick bays, it is necessary to set up multiple pick locations for the most popular commodities.

Placement of storage locations

A reserve pallet storage location that may or may not be above the individual pick faces will be used in a typical warehouse configuration. Depending on the number of SKUs and the quantity of floor space available for both reserve and pick locations, it will either be necessary to segregate the storage area from the pick area or not. This gives the picker the ability to select entire pallets of a product if the order requires it. The picker should not take a full pallet from the pick position since that pallet will need to be quickly replaced by another, adding to the workload.

Picking full cartons

The worst-case situation is when the picker fills a full pallet order of 100 cartons of the same SKU by taking 50 cartons from the pick face and 50 more from the reserve stock. Unfortunately, regardless of the size of the order, some WMSs still operate by the idea of emptying the pick face first.

Picking families of items together frequently

If families of items frequently appear on orders together and constitute a large percentage of these orders picked, it may be beneficial to create a distinct location within the warehouse for these products. Large customers that only order a certain amount of products or customers who have customised products with their own labelling and packaging are two examples. To enhance the number of pick places, especially for smaller, slower moving objects, a mezzanine floor can be built.

Locations of value adding tasks

The necessity to perform value-adding tasks (like labelling or kitting) should also be considered when thinking about an optimal warehouse layout. In order to save unnecessary travel and handling, this location must be close to both the picking and outbound areas. A mezzanine floor, once more, is perfect for this kind of job. Built over the inbound and outbound doors, making the outbound area easily accessible and makes use of "dead" space.

About Powerhouse AI

Powerhouse AI automates inbound, cycle count and stocktake by making checking and counting inventory as easy as taking a picture with a phone. Visit our website for more information: www.PowerhouseAI.com

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