Finding Hidden Warehouse Capacity
Discover new space in your facility
Out of space? You are not alone. With increasing SKUs and inventory levels, many warehouse operators are staging products in the aisles, using outside storage, and mixing SKUs in locations. All of this lowers labor productivity and impacts quality. So, where is the hidden capacity in your warehouse?
The search for untapped space
We realize the amount of inventory is something the warehouse operator cannot change, so we will explore the more obtainable opportunities for finding hidden capacity. The areas of potential include the layout configuration and aisle placement, equipment design, clear heights, location sizing, consolidation and analyzing if you have the right warehouse storage mix.
Focus on the layout
Optimizing the layout is the first objective of squeezing the most capacity out of your warehouse, and this can be conducted in multiple ways. For example, when you look at a printout of your facility layout, how much white space do you see in the storage areas? If you see more than 50%, then you might have too many aisles, and/or they’re too wide.
Taking a closer look at how items are being stored in the warehouse might surprise you. The most common, yet challenging opportunity is to eliminate obsolete inventory – visually identified by the build-up of dust on pallets and cartons. A supportive analysis is to identify the products that have not moved in a 12-month period. Determine the number of pallets, dollars of inventory, the number of locations and cubic feet of space taken up by these “dead” items. The results of this analysis can be stunning and support the removal of obsolete items.
Your inventory profile and lift equipment are both key elements in developing your warehouse layout. There are tradeoffs between labor productivity and space to evaluate and then justify capital costs. In addition, considering the current state of your warehouse utilization influences these decisions. If you are operating at 100% storage utilization, the dock is full, and items are stored in the aisles, your position may trend toward maximizing the storage capacity and making more investment.
Storage equipment considerations
The best approach to reviewing storage equipment is to model your inventory to see the pallets per SKU, and optimize the type of storage equipment based on that number. Increasing the depth of storage for items with a high number of pallets per SKU on-hand improves the density of storage, resulting in fewer aisles and more storage capacity. It also saves labor to have those pallets together vs. spread across the building in a single deep rack. Integrating item velocity into the equation identifies the slowest moving items and the potential for isolating them into a very narrow aisle configuration with the use of turret trucks and/or operator-up order pickers (for case handling).
Storage heights – pallet considerations
The unit load height is another factor for selecting the right storage equipment. It is not likely that all pallet unit loads are the same height, which means a variety of location heights can be used in the warehouse. Evaluate the “standard” inbound pallet heights from vendors and profile your rack elevations to the optimal heights.
While inventory levels are trending up for many, there is also the opposite situation, where partial pallets are the norm in receiving. These “short,” often single-level pallets can be stored in 24 to 36-inch pallet location heights. Multiple location sizes can increase put-away times when finding the right location, but a good WMS can be loaded with the location size and the item dimensions to direct the put-away activity. The decision on the pallet location heights should be carefully evaluated to ensure capacity is not negatively impacted.
There has been increased discussion regarding the width of pallet rack beams in a standard selective rack, including the consideration of nine-foot and twelve-foot compared to the traditional eight-foot. The biggest factor is the size of the pallet being stored, and then evaluating which option gives you the most capacity in a rack row. With the use of standard GMA pallet sizes 48 (depth) x 40 (width), eight-foot is the predominant beam length, while twelve-foot racks are increasing in usage.
A common warehousing practice is to use tunnels or bridges above the travel path within the storage area. Tunnels provide a travel path or crossing aisle for improved material flow and labor savings. Local egress codes often dictate the placement and number of tunnels. When using tunnels, you should include as many levels bridging the space above the travel path as feasible with given lift trucks.
A more detailed evaluation involves the actual size of the upright (depth and column sizes) and the beam height structures used to design the storage equipment. A structural engineer designs these sizes to support the load weights, but you may find slight variations in the resulting options. Do not underestimate the impact of an inch change in these dimensions in gaining another bay or level of storage capacity.
Building height is another factor
The clear height of your building is yet another major factor in getting the most capacity out of your facility. Besides the obvious use of racking vs. floor storage for low stackable items, you want to maximize the height of storage in your warehouse. This is another item impacted by local codes that define the maximum storage heights allowed. Based on these codes, the levels per storage bay and the top of the load should be at the highest feasible position.
Unfortunately, the depth of the receiving and/or shipping dock is often the first place encroached upon to gain storage capacity. It is very tempting to add a bay or rack at the end of rows and eat into the dock staging space, but ironically, this could end in more pallets staged in the aisles. Take a good look at the inbound and outbound volumes to ensure there is enough dock space provided. If the staging space is adequate, then the additional end-of-row bays could be a good solution.
Just the beginning
There are many other considerations to getting the most capacity from your existing warehouse space:
- Stack-rack used for odd-sized items currently staged one-high on the floor
- Racking above dock doors for empty pallets and corrugate
- Freestanding mezzanine to free up space for storage equipment
- Product slotting to right-size pick locations
- Double-stacking pallets on top-level if feasible
- Location consolidation for like SKUs (with no lot/date code restrictions)
Take a good look at your layout and related data and the topics covered in this issue to uncover the potential of your hidden storage capacity within your existing warehouse.