Four Simple Questions for Improved Picking Performance
The process of receiving a product into inventory is just as important as picking or removing it from inventory. A solid slotting plan for receiving and storing products in a facility supports quicker and more accurate picking.
Slotting is the concept of using data analysis to assign every part a location based on its specific attributes. While the work involved in slotting items in a storage system can be complicated, at its core are four simple questions:
1. What is the best storage equipment for this item? Matching an item to the appropriate storage equipment is the most important factor in slotting. Companies often settle this question, however, by using storage practices they already have in place.
Equipment options range from carousels to racks to drawer cabinets. Most storage systems can operate well with just a handful of storage zones. It is important to review each part individually and take into account not only how much space is required, but also how often that part is accessed.
Tip: Parts often need to be stored in various quantities in more than one storage location or device for efficient material flow.
2. How many of each part do we need to store? The answer to this question will almost always be "as few as possible." For medium-sized and medium-velocity stockkeeping units (SKUs) stored in a horizontal carousel, a good rule of thumb is to keep a 20-day supply. This quantity provides a sufficient amount of stock without requiring frequent replenishment.
Tip: Sometimes the number of parts that should be stored doesn't match what is currently stored. Don't be afraid to make a change.
3. What size storage location (cell) should be used? Keeping the number of cell sizes to a minimum allows random storage to be incorporated effectively, makes the loading process a breeze, and limits "paralysis by analysis."
Tip: Churning data can only take you so far. A hands-on approach is always best, so go to the warehouse, look at the different cell sizes, and decide whether or not they are appropriate.
4. Where does the cell go? Put the faster-moving items in cells that are easy to access. It is important to examine the storage equipment and decide if there is a tactical advantage to storing fast movers in them.
If there is, determine the best way to get your fastest movers into those cells. It is often a good idea to postpone this step until you are at least partially through your slotting exercise so you know how many of each cell size will be available.
Tip: Consider pick density when configuring cell layouts. For example, it is often better to store four smaller, medium-moving parts that get four daily hits in a prime, accessible space than one larger, fast-moving part that gets 10 daily hits. By storing the four medium-moving parts, the prime space will get 16 daily hits instead of 10.
Everything In Its Place
Slotting an entire warehouse is a sizable undertaking, but the rewards greatly outweigh the time investment. When done properly, slotting can support a number of lean objectives, such as reducing obsolete inventory, minimizing stock quantities, and decreasing part retrieval times to improve flow.
To get the ball rolling, focus on the fastest-moving parts in your warehouse. Ensure you are storing them in an efficient quantity and location, and gauge the immediate benefits gained from the process. You'll be on your way to total slotting success.