What is honeycombing in a warehouse?
Honeycombing is warehouse space that is empty but cannot be used, because it sits in a lane or location that already belongs to another product. It happens wherever a lane is more than one pallet deep and holds one product at a time: drive-in, push-back, pallet flow, shuttle lanes and block-stacked floor rows. As pallets leave, the lane’s empty places wait for the last pallet to go before a new product can move in.
The rule. A lane k pallets deep that fills with one product and empties evenly is, on average, (k − 1)/2 places short of full. A 6-deep drive-in lane loses 2.5 places on average, a 12-deep shuttle lane 5.5. The same happens upwards when pallets are block-stacked on the floor.
What it does to capacity. The loss is largest when each product has few pallets. In a 60 × 50 m freezer with 7 pallets per product, 6-deep drive-in racking has 7,440 places and holds 1,608 pallets on an average day; selective racking, with no lanes to honeycomb, holds all 5,400 of its places. With many pallets per product the gap closes.
Lane depth is the lever. Deeper lanes save aisle space and waste more to honeycombing, so there is a best depth. Bartholdi and Hackman derive it as roughly √(a/2 × q/z): a is the aisle width in pallet depths, q the pallets per product, z the levels it is stacked. More pallets per product, deeper lanes.
The long version, rack type by rack type: Storage density vs selectivity. Related: What is a pallet position?, Cold storage racking: which rack type for a freezer or a chiller
Sources
- Bartholdi, J. J., & Hackman, S. T. Warehouse & Distribution Science, release 0.98, §6.1, pp. 56–58: honeycombing waste and optimal lane depth.
- Room figures: the cold store tool engine, frozen room, 400 moves a day.