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Short answer
The 8 wastes of Lean, remembered as TIMWOODS, are Transport, Inventory, Motion, Waiting, Overproduction, Over-processing, Defects and unused Skills. In a warehouse they show up as double handling, excess and dead stock, long picker walks, queues at docks and staging, picking ahead of demand, extra checks and touches, picking and stock errors, and floor teams whose ideas are never used. Waiting and motion are usually the largest.
Every warehouse manager knows the floor is busy. Fewer can say how much of that activity actually moves an order closer to the customer. Lean answers that question by naming eight kinds of waste: effort and time the customer would never pay for. Learn to see them on a floor walk and you will find capacity you did not know you had, before you spend on space, people or equipment.
T: Transport
Moving material more than the flow needs. In a warehouse that means pallets dropped in a staging lane, moved to a buffer, then moved again to their location; or reserve stock stored far from the pick face it feeds. Every extra move adds time, equipment hours and damage risk.
I: Inventory
Stock beyond what the next step needs: excess, slow-moving and obsolete items occupying prime locations, and work piling up between processes. Inventory hides every other waste, and on a value stream map it shows up as hours of waiting once you convert units to time.
M: Motion
People moving more than the task needs: pickers walking long routes to fast movers stored at the back, searching for the right location, bending to floor-level heavy items, leaving the route to find reserve stock. Travel is often the largest share of a picker's shift, and it is set by slotting and layout, not effort.
W: Waiting
Material or people idle. Trucks waiting for a free dock, goods sitting in staging for inspection, pickers waiting for replenishment or order release, packed orders waiting for dispatch. In most warehouses waiting is the single biggest share of lead time, and it is almost invisible until you map it.
O: Overproduction
Doing work before it is needed: picking or kitting ahead of the dispatch or production schedule, staging orders that then sit and block space. It feels productive, but it creates inventory, motion and errors downstream.
O: Over-processing
Effort that adds nothing the customer values: re-labeling, re-counting, double scanning, repacking, approvals that exist because nobody trusts the first check. Most over-processing is a symptom of an earlier step that is not reliable.
D: Defects
Errors and the rework they cause: wrong picks, short picks, damaged goods, stock records that do not match the shelf. Each defect costs the correction plus the investigation, and inaccurate records trigger more waiting and searching across the whole operation.
S: Skills (unused talent)
The eighth waste is people. Supervisors and operators usually know exactly where the floor loses time, but there is no routine to capture and act on what they see. Lean improvement works best when the floor team builds the change.
How to spot the 8 wastes on a floor walk
- Follow one order from the dock to dispatch and note every stop, move and touch
- Count how many times a pallet is handled before it reaches its location
- Time a picker's route and how much of it is walking
- Look for material sitting still: staging lanes, buffers, packed areas
- Ask the floor team where they lose time; write down every answer
Which waste to attack first
Start where the time goes, not where the activity is. Map the flow, convert inventory to time and look for the largest waits; they usually point to transport, motion and inventory problems upstream. That is the Measure and Analyze stage of DMAIC, the Lean Six Sigma cycle we follow on every engagement; see our Lean Six Sigma approach.
To check your own building, walk it with our free Warehouse Capacity Self-Check, or book a free 30-minute call and we will help you find the biggest waste first.