Product slotting optimizes your warehouse layout

Product slotting optimizes your warehouse layout

Product slotting in a bin location in your warehouse is one of the most complex things to do but the concepts associated with it are actually quite simple. In this article I am going to explain what product slotting is, why it is important and the very strategy to do it.

What is product slotting

In our two-part series on Warehouse layout we analyzed extensively how to organize the warehouse and how to assign products to different locations in the warehouse. The focus of those articles was how to distribute your racks in the warehouse and how to define the best picking route based on the Pareto rule which states that approximately 80% of the activity in the warehouse comes from 20% of the products (see “Warehouse Layout Optimization – Part II: Pick Path & Product Location”).

Slotting, on the other hand, basically refers to the placement of products groups or SKUs in bin locations, given your existing layout. We will expand on this in the next section.

Is product slotting the same as warehouse layout?

In essence, they are the same in the sense that they both address the same end goal, which is: How to organize the warehouse and allocate products to optimize picking and put way. But rather than similar they are complementary:

Warehouse Layout, sometimes referred as Macro slotting, refers to optimizing the overall layout of a warehouse. When your warehouse layout design is completed, you end up with racks arranged three dimensional and products assigned to rack positions based on rules to optimize picking time.

Product slotting or Micro Slotting refers to how specific items should be placed in specific locations in the warehouse based on product features and sales statistics. It considers the product sales speed, dimensions, weight, and shelf life. When you add this dimension and take into account how fast the product moves, how fast it sells out of your warehouse, how big or heavy the product is and, last but not least, when the product is going to expire you can determine where to place the product in your warehouse and in what sequence to pick them.

Product slotting strategies

Stack products from heaviest to lightest: If you are going to stack products on a pallet to be delivered, you want to put the heaviest products on the bottom of the pallet. If you put heavy products on top of a light product, you can damage the first one. So, if you want to optimize the picking time you should place the heaviest products on the rack columns closer to the designed forklift route in the warehouse layout.

Fastest rotating products: The fastest rotating product will be picked frequently for different orders. Consequently, you will want to place the fastest rotating products at the bottom of the racks and the slowest products at the top, because the products at the bottom are picked faster than the ones on the top. If the fast moving product is not at the bottom and you pick it with a forklift, you need to raise the forks, pick them up, and then lower them. If the pick is manual, you need to place the ladder, climb up, pick up and go down. In short, the picking time will be longer.

Shortest shelf life products: On the same token, products with a short expiration time should be picked first over products that have longer expiration date. Therefore, you will want to place products with a short expiration date at the bottom of the racks and those with longer expiration date at the top.

Conclusion: In summary for product slotting you want to go heaviest to lightest, fastest velocity to slowest velocity from bottom up, and you want to go fastest expiring to longest shelf life from bottom up. The graph below illustrate the concept.

This strategy will yield less product expired, much more accurate pickers, a lot less waste when it comes to picking heavier product over lighter product and, overall, it’s going to allow your staff to be 10 times more efficient when they move up and down the warehouse from beginning of their picking sequence to the end.

Why is product slotting important?

Slotting is a fairly complicated process that requires precise analysis of SKUs and transaction data. If your WMS supports it, you should consider using it. Adding slotting will give you the following benefits:

• Improved order picking and put-away efficiency.
• Reduce product damage during picking.
• Reduce product expiration

I hope this article has been helpful to you. I will continue to post information related to warehouse management, distribution practices and trends, and the economy in general. If you are interested in this article or want to learn more about Laceup Solutions, please subscribe to stay updated on future articles.

There is a lot of relevant information on our channel. Check out this video on this topic.