Warehouse Layout and Slotting: Cut Picker Walking Time

In most warehouses, pickers spend more time walking than picking. Better slotting, meaning which product lives in which location, is one of the cheapest ways to speed things up. No new software, no new racking. Just moving products to better places.

Start with velocity

Pull 90 days of picks from your ERP and rank products by pick frequency (number of pick lines), not by units sold. A product picked 500 times a day as single units matters more for walking time than one picked 20 times in pallets.

Then group them:

• Fast movers. Top ~10-20% by pick lines
• Medium movers
• Slow movers. The long tail

Put fast movers close and at the right height

• Fast movers go nearest to packing and dispatch
• And in the golden zone, roughly waist to shoulder height
• Heavy items go low, light and slow items go high
• Spread the very fastest across a few aisles so pickers don't queue in one spot

Keep things that sell together close together

Look at order data for products that appear on the same order often. Phone and case. Filter and cartridge. Placing them close together shortens multi-line picks.

Separate pick faces from reserve stock

A common, effective pattern:

• Pick faces. Small, accessible locations holding a few days of stock
• Reserve storage. Pallet racking holding the rest

Then replenish pick faces from reserve with min/max rules on the pick-face location. In Odoo, that's a reordering rule on the pick location with a route that pulls from reserve.

Name locations so humans can follow them

A good location code tells a picker where to walk. A common format:

Zone - Aisle - Rack - Level - Bin, for example A-03-12-2-B

Rules worth following:

• Use the same number of characters for each part, so codes sort correctly (03, not 3)
• Number aisles in walking order
• Label every location with a barcode, at a height that's easy to scan

In Odoo, locations nest naturally (WH/Stock/A/03/12...), and each location also has X, Y and Z position fields, which is handy if you later want to visualise the warehouse in 3D.

Fix the pick path

Even a well-slotted warehouse is slow if the pick list jumps around. Make sure pick lists sort by location in walking order. If your location codes follow the walking order, sorting by code is enough.

Measure before and after

Pick a measure and track it:

• Lines picked per hour, per picker
• Average distance or time per order
• Pick errors

Change one zone first, measure for two weeks, then roll out. It's easier to persuade the team with their own numbers.

Re-slotting is a habit

Demand changes, so slotting goes stale. Review the top movers monthly. Before peak season, do a proper re-slot.

Related: warehouse management system guide and Odoo inventory routes explained.