Warehouse heat map: from an Excel template to a live floor plan

Spatial Map is a live indoor map for warehouses and other facilities, and it can show any layer of points as a heatmap on the floor plan. But a warehouse heat map is not one thing. Ask four operations people what theirs shows and you will get four answers:

• Pick density — how many pick lines each location or aisle served over a period. The classic input to slotting.
• Congestion — where pickers, forklifts and carts bunch up, and when.
• Travel — which paths people actually walk or drive, and how far.
• Stock and space — which locations are full, empty, low or blocked right now.

The common template is a grid: aisles across, bays or levels down, each cell holding a pick count exported from the WMS, coloured with conditional formatting. Power BI, Tableau or Looker do the same with a matrix visual or a picture of the layout behind it. For a quarterly slotting review this is often all you need.

• The grid is not the building. Templates draw every aisle the same length and ignore cross-aisles, mezzanines and the dock. Travel looks shorter on paper than on the floor.
• Locations get renamed. After a re-rack, half the codes in last quarter’s export point at cells that no longer exist, and the template quietly drops them.
• Picks are not effort. A pick from the top level of a high-bay rack costs more than one at waist height; weight by level or by handling time if you can.
• One snapshot, then nothing. The heat map is built for a meeting and never refreshed, so the slotting it justified is never checked.

None of this makes the spreadsheet wrong for slotting. It means a spreadsheet answers “what happened last quarter?”, and a map answers “what is happening now, and where exactly?”.

Two notes. Positions come from your RTLS, BLE gateways or RFID middleware; Spatial Map shows them but does not compute them from radio signals — see RTLS software for how that split works. And for “which areas are full right now”, a density heatmap is the wrong tool: you want each rack location coloured by its own value, which is a style rule on the rack cells, as in CSV bin inventory to a live rack map.

In the facility viewer and on report maps, the Heatmap control turns any point layer into a heatmap. Its options are short:

The detail that matters most in a building: heat stops at walls and closed doors. A busy packing room does not glow into the quiet returns room behind its wall, and a cold store behind a closed door stays its own space. When you tilt the map in 3D, heat behind a wall is hidden rather than painted over it. More on the feature on the indoor heatmap software page.

Rack locations coloured by stock status

1. 1
   Trace the warehouse once

   Import the floor plan, draw the walls, doors, racks, docks and staging lanes. Rack locations get the same codes your WMS uses.

2. 2
   Bring the data in as a table

   Upload a CSV or XLSX of pick lines per location, let a script write rows through the table’s API, or schedule a pull from a REST endpoint. RTLS positions go into their own table with longitude and latitude.

3. 3
   Link the table to the map

   Match rows to rack cells by location code, or place them by coordinates. Add the fields people want in the tooltip.

4. 4
   Turn on the heatmap

   In the viewer, pick the layers, choose the weight and the floor. The same control is on a full-map report, for a view the team opens every morning.

Live stock by bin on the rack map

• Normalise before you compare. Two aisles with equal picks are not equal if one has twice the locations.
• Pick the period on purpose. A peak week and a quiet month tell different stories; keep both.
• Mind the gaps. No heat can mean no activity — or no sensor coverage. Check where your readers and gateways are.
• One question per view. Congestion and pick density in one colour ramp is unreadable; use separate layers.
• Act, then look again. After a re-slot, compare the same period before and after.

The Crestline Fulfillment Center demo has the parts to try this on: 20 racks with 2,204 locations, pick modules, staging lanes, docks and forklifts on one map. Start a 7-day free trial to do it with your own layout — no card, up to five facilities; Pro is $60 a month for up to four.