Warehouse Layout Design – How to Maximise Space

Warehouse Layout Design Part 1: “The ever faithful warehouse manager, Wally and the WW2 relics.”

Warehouses are of course designed to store yours or your customers goods but “like work expands to fill the time available”, the same can be said for stored items in your warehouse.

“Product will expand to fill the space available!”

So how do you keep your warehouse running at the most efficient capacity without having to rent or lease additional warehouse space? There are a surprisingly large number of ways to maximise your warehouse capacity and increase the number of pallet positions stored with clever warehouse layout design. Of course those in the warehouse, logistics and supply chain industry are well aware of the additional pressures past on by customers, end users and those pesky people in production or good inwards that simply keep sending you an ever increasing volume of pallets!

This is of course made even more challenging when you add in things like seasonal demand and rapid growth of sales. The purchasing manager’s sudden announcement that he has secured some large bulk buying discounts so could we slip in a few extra hundred pallets. Or of course at the other end of the process poor sales meaning less pallets leaving the warehouse or the MD decides that “A programme of consolidation is required to drive efficiency”. Which for warehouse managers usually means a satellite warehouse or an area of the existing warehouse is commandeered and you face a “new and exciting challenge”, as to where to store the further six hundred pallet positions!

Having considered the points above the ever faithful and helpful warehouse manager has now found himself in a position even though he is still not quite sure how it happened. That somehow he seems to of agreed to store thousands of extra pallets with no extra floor space. Although the FD has been kind enough to allow him a few thousand pounds out of the many thousands the FD has saved on the bulk buying and “the programme of consolidation that is required to drive efficiency” to buy a bit of extra pallet racking.
After a brief period of reflection and upon the realization that he is unlikely to win the X factor or this week’s lottery the warehouse manger decides to confide in his deputy.

His deputy offers a solution “why don’t you call that guy Wally, you know the blokes been in before trying to sell that used racking.”

Now the warehouse managers mind drifts back to the time when Wally was in before. The warehouse manager remembers his exchange of words with Wally “What’s it like then Wally is it good quality?” Wally helped him out by showing him some pictures on his phone of what appeared at first glance to be some WW2 relics that had recently been hauled out of a river. The warehouse manager also remembered asking Wally if he “knew what he was doing and would it be safe to SEMA standards etc”. Wally’s reply had not filled the warehouse manager with confidence “don’t worry about all that, I’m telling you we’re cracking at racking”.

Warehouse Layout Design Part 2 – When Wally wont do

Consider your inventory before you spend time and money on a new warehouse layout design. Although many in your company will drive for high volumes of the right product in stock there is a tipping point where it will effect warehouse efficiency and potentially put warehouse staff in danger. It’s easy to spot those tell tale signs that the ware house is getting over loaded. Pallets and stock starts to appear in aisles for increasing lengths of time. Or docking areas become full of pallets, P&D stations (the picking shelves on rack ends) are used to store pallets. Or left over pallets sneak their way into the wrong locations as the correct locations are over full. This is simply dangerous with reduced warehouse visibility, decreased labour and truck run efficiency and multiple handerling of product. It also creates that feeling of rush and panic which can lead to warehouse staff cutting corners and safety being compromised.
Another potential area of consideration is have you got too much of the wrong product? Have you got obsolete or out of date product buried away in the ever increasing number of pallets. This again is a team effort to rectify. It requires good sales forecasting and production planning but also good inventory control. It is the responsibility of the warehouse manager to flag the issue with a clear and concise warehouse inventory report.

Pallet racking design and product change.

When warehouses are first designed a design brief of some type is produced it may simply be a verbal instructions to the pallet racking supplier on number of pallet positions, pallet weights, sizes and preferred handerling face. Or it may be a detailed CAD drawing, however good your pallet racking installers are things change. Suddenly you find that some product comes in heavier pallet loads so storage on the pallet racking beams is no longer an option. Unsure that increased beam loadings will solve the issue as the uprights and frames may not take the loadings, ground storage is the only option. So product starts to appear in ever increasing quantities on the ground while pallet positions on the pallet racking remains empty. This can be a quick and vicious spiral as pallet racking positions become increasingly more difficult to safely access because of the block and ground storage around them.

Now unless you can increase physical warehouse square meterage by extending or building a new warehouse you really have only three main options.

Testing, measuring and improving warehouse inventory reporting.
Increasing pallet positions stored by leveraging yard and outside storage.

Reconfiguring your warehouse layout design

Warehouse Layout Design Part 3 – Mezzanines and pallet racking design

The solution to increasing warehouse capacity.

When you have considered all options such as temporary off site warehouse which can be costly particularly in the short term and at periods of high demand you are left with two main options. The first is outside or yard storage where pallets are either block stored or stored in galvanised pallet racking. This option suits few businesses even as a short term solution due to damage to stock from the weather in external storage.

The second and more long-term strategy is to redesign the warehouse layout, although there is a cost it can be controlled and a clear return on investment shown.

Once you have decided to redesign your existing warehouse facility it is important to stay focused on clear goals you need to achieve.
The first and most obvious is to utilise the existing space in the most efficient manner.

Make sure you allow for material handling in the most efficient ways. It is a good idea to get some input from all the warehouse team. They may have some good ideas and it helps them get behind the new changes.

Provide the best return on investment from the new design. This can be achieved by considering using used pallet racking, or reconfiguring and adding to the existing pallet racking. However consider the age and condition of the storage equipment.

Consider the flexibility of the new configuration as things can change over time.

Make sure your new warehouse design promotes good housekeeping, safety and best practice.

Warehouse Layout Design Part 4 –  Warehouse layouts & rack designs

Warehouse design follows a few simple principles, size shape and obstacles of the building, number of pallet positions required to be stored. The majority is simple common sense, but there is no substitute for experience.

Pallet racking installers and pallet racking suppliers do this every day so they get to see which rack configurations in which type of buildings give optimum performance. They will look at pick rates truck sizes, despatch and goods inward and use their experience of similar projects to specify the best warehouse and pallet racks.

They can also advise on additional extra options like rack frame upright protectors, rack end barriers, and staff racking safety training. In a fast moving and busy warehouse environment these can literally save thousands of pounds of pallet racking repairs.

Below are the critical steps to design and specify your optimum warehouse layouts

1. Measure the space you have to use.
2. Add in items that are fixed and can disrupt with work flow, fire doors, walls, steel columns and portal frames (remember frame gussets at eves and wind braces) and include clearance for maintenance and pest control (300mm is often recommended)
3. Define product or pallets stored, widths, depths, height, handerling face, overhang, weights, etc.
4. Consider throughput and stock replenishment and any defined storage condition zones.
5. Now consider the best material flow paths (this is when experience provides value).
6. Locate other auxiliary fixed items, offices, toilets, docking areas, holding areas, inspection and dispatch.
7. Generate and evaluate alterative.

Warehouse Layout Design Part 5  – Warehouse rack manufactures and product options

Once you have a basic plan of which areas can be designated to storage equipment warehouse racking or shelving, it is time to look back at the inventory to help you best decide what type of pallet racking or combinations suite your unique storage requirements.

So looking at the stock is a percentage of this stock suitable for high density storage? If some of your product is not date sensitive and does not need to be picked in a certain order this stock is suitable for the highest density storage. This will probably be in the form or drive in or drive through pallet racking, to get the maximum density and benefit drive in and drive through pallet racking works best in most situations when designed in large blocks.

For example the pallets might be stored in the drive in pallet racking as follows, 6 pallets deep, 10 pallets wide (lanes) and 4 pallets high. This would give you 240 pallet positions in one block area. Drive In pallet racking stores pallets on a FILO (first in last out) basis whereas Drive Through pallet racking stores pallets on a FIFO (first in first out) basis. For all Drive Through pallet racking systems two aisles are required, one to load pallets and one at the opposite end to unload pallets.

This then leaves the rest of the available space to be taken up with APR or adjustable pallet racking, you may choose to have all the warehouse racking the same to allow for alterations and simplicity of repair. Or you might opt for some runs to be built to a lower weight rating for lighter goods like packaging.

Look at different pallet racking manufactures, some systems will suit your stock better than others, so chose an independent supplier who can search the market for the best products for you.

Each warehouse has to make a compromise between the number of pallet positions stored and the number of pick positions.

Another consideration is the type of pallets stored this is one of the most critical decisions for APR you can opt for 900mm or 1100mm frame depths. This affects the type and handling faces of the pallets to be stored on the warehouse racks.

A careful consideration is required if you have mixed stock the advice of an experienced pallet racking designer will be required. If you get this wrong the return on investment from the pallet racking will be drastically reduced.

Again looking at the stock or product held in the warehouse, adding mesh or timber decks can be a worthwhile investment. These allow for unpalletised items or varying pallet sizes to be stored in different positions, however be careful as the load will still need to be evenly distributed over the pallet racking beams. Pallet Support bars might also be an option to help store pallets safely.

Warehouse Layout Design Part 6  – Warehouse racking design options

One of the first and sometimes easiest ways to obtain better storage density is to look at vertical height density. This is simpler than it sounds, take the average load height with the pallet included and times this by 75-80% of the buildings height. This will be a good guide as to the number of pallet positions available in the height of each bay.

It is not uncommon to find pallet racking installations that are at 50% leaving large gaps above the pallets and wasting expensive warehouse space. You can also tighten up pallet clearance spaces for less picked and slower moving pallets. There are other more complex and costly options to maximise vertical storage density by using pallet orientation with decked levels and case flow racks for slow moving stock.

One of the most rarely used methods of increasing storage space by between 5-10 percent is to tunnel over aisles. This method requires netting, staff rack and forklift safety training and bespoke fabricated beams to allow levels to be created between double entry racks above the aisles.

A more popular option is to create rack over docks, so when loading is not being carried out stock can be loaded or unloaded into these racks. Again this is best used for the slower moving pallets in the warehouse.

Warehouse Layout Design Part 7 – Mezzanines and narrow aisle forklift trucks (N.A.F.L.T)

Mezzanine floors are a popular way of adding space and offer an ideal opportunity to compartmentalise some operations. They are often used to keep office operations safely away from fork lift trucks and production areas allowing noise and dust to be minimised. Mezzanine floors are the perfect solution for some businesses but it really depends on the unique requirements of each business.  Mezzanine floors are sometimes classed as value added service areas and discussed by designers and architects as VAS. They can be a good option when a company is looking at value engineering and can negate the need to lease or buy a separate office building.

The next options are narrow aisle (NA) very narrow aisle (VNA) and fork lift trucks like Bendi fork lift truck technology has improved dramatically in recent years. This has allowed warehouse rack aisles to reduce dramatically in width allowing a far greater number of pallet racks to be installed in some buildings. Some fork lift trucks can now operate in aisles down to just over 1.6mtrs considering that pallet racing layouts usually work on 2.8-3mtr aisles the space saving is obvious.

Another option is to look at double deep, push back or pallet flow warehouse rack designs. These systems can be costly per pallet stored but as part of a larger scheme can offer the best value for warehouse operations that need speed and a low number of operators. This is where a good return on the investment can be achieved.

Remember once the ultimate warehouse system has been designed the last thing to consider is your warehouse review policy, small and simple adjustments to beam levels or alterations to pallet racking will keep your warehouse running to the maximum efficiency possible.

In business the market place is constantly changing, the key to a successful warehouse is flexibility being able to react to short term needs while staying focused on long term goals and projections.

We hope you have enjoyed this short series of blog posts on maximising warehouse space, the key is to get your design to work for your needs. Why not give us a call to get some project ideals and advice?

Richard Haynes has been in the industrial warehouse industry for many years. You can find him on <a rel="author"