We all know pallet racking can’t forever be 100% full, even though that’s what some people will make you believe. So what kind of utilisation can you achieve and what should you use for your warehouse, especially when you’re first designing your facility?
There are several schools of thought and you will find that, when you talk to different people, you will get slightly different results. We tend to be conservative in our calculations to ensure our customers have a little bit of leeway to cater for unexpected peaks.
“Drive-in racking only has a 75-85% utilisation”
There are roughly 7 different types of pallet racking which are commonly found in Australian warehouses:
- Single deep selective pallet racking
- Double deep selective pallet racking
- VNA (Very Narrow Aisle) single deep selective pallet racking
- Drive-in pallet racking
- Satellite pallet racking
- Pushback pallet racking
- Mobile pallet racking
Each of these pallet racking types has a different utilisation factor, due to their design. For instance, selective pallet racking can achieve up to 100% utilisation because each location holds exactly 1 pallet and each location is accessible individually, however, for sizing purposes, we use 95% to leave some room for inbound pallets, replenishment, etc.
So to store 10,000 actual pallets you need 10,527 pallet locations (10,527 * 95% = 10,000).
“It is very hard to modify pallet racking once it’s installed”
Drive-in racking on the other hand only has a 75-85% utilisation because each rack lane is intended for the storage of a single SKU/batch/expiry date combination.
For instance, if your drive-in racking uses racking that is 4 pallets deep by 5 pallets high, you can fit 20 pallets into a single drive-in rack. But when did you ever manage to have exactly 20 pallets of a single SKU/batch/expiry combination in stock? When you receive stock in, either from production or external sources, you might end up with exactly 20 pallets at some stage, which will give you 100% utilisation but, once you start despatching to your customers, your utilisation will deteriorate again until the rack is completely depleted of that 1 SKU/batch/expiry combination and you put in a new SKU/batch/expiry combination.
But which type of pallet racking is best for me?
That’s a very personal question and one that I cannot answer simply by looking at the available types of pallet racking available. If your business is an ecommerce business despatching individual units to customers compared to a wholesale business that despatches in full pallets will greatly impact the types of racking applicable to your business. Some of these factors include:
- Type of business
- Expected growth
- Seasonality
- Stock turnover
- Stock on hand requirement(s)
- Batch sizes (if applicable)
- Order profile(s)
The list goes on, but you get the drift. To determine the best type of pallet racking and the optimal quantity of each, we recommend running a full data analysis before making the decision. The difficulty with pallet racking is that it is very hard to modify pallet racking once it’s installed. Yes, you can add/remove some beams but changing from selective pallet racking to drive-in racking is not easy. It is therefore imperative that you ensure you choose wisely before you commit!
But how much space do I need?
I’ve compiled a small table that will provide an indication to the space requirements, expressed in pallets per 1,000 sqm based on using standard aisle widths, which you will find below. This will at least give you an indication when you are first looking at fitting out your warehouse.
What if I get it wrong?
You’re stuffed! That may be a bold statement to make but because pallet racking is bolted to the floor and you have filled it with stock, it’s very hard to change pallet racking once it’s installed. Adding or removing a few beams on selective pallet racking is relatively straight forward but changing from drive-in racking to single deep selective is a huge undertaking without even looking at the cost implications.
The only advice I can give you is to get an expert involved to help determine the optimal mix of pallet racking. You’re about to purchase something that needs to last you at least until the end of your lease term, if not longer, which is not an easy decision.
Get it wrong and you can be facing the consequences for a long time to come.
Get it right though, and you’ll be reaping the benefits for a long time as well.
One last thing I need to add.
Start with your racking concept first and then find a building that suits. Most people start with a predetermined building footprint/layout and then try and squeeze a racking design into it. The result is that you’ll have to make compromises to fit the column grid, the positions of staging/docks/etc. For instance, the standard column grid in Australia suits a combination of single deep and double deep selective, to make the most of the available space, but if you only store 1 pallet of each product double deep pallet racking is useless and will actually make your warehouse inefficient.
Good luck!
About the author: Bas Schilders is the principal consultant at Fuzzy LogX who are the leading warehouse, logistics, and process improvement consultants in Australia. With a career spanning 2 continents and 20 years in warehouse improvements and solution implementations, Bas is one of the most experienced consultants in the country when it comes to logistics improvements and implementing warehouse automation solutions.