Definition
Motion waste is unnecessary movement by operators during their work — walking to get parts, reaching for tools, bending to pick up materials from the floor, turning to access equipment behind them, searching for items that are not in their designated location. Motion waste refers specifically to the movement of people, not the movement of materials (which is transport waste).
The distinction between work and motion is fundamental: work transforms the product in a way the customer values. Motion is everything else the operator’s body does. Picking up a part and installing it is work. Walking across the aisle to get the part is motion. The goal is to maximize the proportion of work within each cycle and minimize everything else.
Japanese Origin
動作 (dōsa) combines 動 (dō, “move”) and 作 (sa, “make, do, action”). It means “movement” or “action” — specifically physical movement of the body. In industrial engineering Japanese, 動作 is the standard term for operator motion and is used in motion study (動作研究, dōsa kenkyū) and motion analysis.
Ohno distinguished between two types of human activity on the shop floor:
- 動き (ugoki) — movement, motion (not necessarily productive)
- 働き (hataraki) — work (productive, value-adding activity)
Note that 働き uses the same character (働) that Toyota inserts into 自働化 (jidoka) — the character with the “person” radical. Real work (hataraki) involves a person adding value. Mere movement (ugoki) may look like activity but accomplishes nothing for the customer. Ohno’s challenge to supervisors was always: “Is that person working, or just moving?”
The Gilbreth Connection
The waste of motion has its deepest intellectual roots in the work of Frank and Lillian Gilbreth, American industrial engineers who developed motion study in the early 1900s.
The Therbligs
Frank Gilbreth created a taxonomy of fundamental hand and body motions called therbligs (an approximate reverse spelling of “Gilbreth”). The original Gilbreth taxonomy contained 17 elements. An 18th — Hold (maintaining an object in a fixed position so the other hand can work on it) — was added later by Allan Mogensen and subsequently adopted by Ralph Barnes in his influential textbook Motion and Time Study. Some IE references list 17 therbligs, others 18, depending on whether they include Mogensen’s addition.
This is a recurring pattern in the IE and lean tradition: an original framework gets expanded by later authors. Toyota’s original 4S became 5S when Osada and Hirano added shitsuke (discipline) for audiences outside Toyota. Ohno’s 7 Wastes became “8 wastes” when Western consultants added “unused talent.” In each case, the original creator’s framework was sufficient for its purpose; the addition reflects a different author’s context or audience, not a gap in the original thinking.
The therbligs break down any manual task into its most basic components:
- Search — eyes or hands seeking an object
- Find — locating the object (end of Search)
- Select — choosing among several objects
- Grasp — closing fingers around an object
- Hold — maintaining an object in a fixed position (added by Mogensen)
- Transport Loaded — moving an object from one place to another
- Transport Empty — moving the empty hand to reach for another object
- Position — orienting an object for the next operation
- Pre-Position — placing an object in a predetermined location for future use
- Assemble — combining two objects
- Use — manipulating a tool or object for its intended purpose
- Disassemble — separating two objects
- Inspect — examining an object for quality
- Release Load — letting go of an object
- Rest for Overcoming Fatigue — pause due to physical tiredness
- Unavoidable Delay — waiting caused by the process itself
- Avoidable Delay — idle time within the operator’s control
- Plan — mental hesitation, deciding what to do next
Of these, only a few (Use, Assemble, Disassemble) are truly value-adding. The rest — Search, Select, Transport Empty, Position, Pre-Position, Inspect, Hold — are the individual motions that constitute motion waste when they are excessive or unnecessary. The Gilbreths’ insight was that these motions could be systematically studied, measured, and reduced.
From Therbligs to Toyota
Japanese industrial engineering inherited the Gilbreth tradition through American industrial engineering textbooks and the postwar technology transfer programs. Toyota’s standardized work system — which specifies the exact sequence of hand and body movements for each operation — is a direct descendant of Gilbreth’s motion study, applied within the framework of takt time and cycle time.
When a Toyota industrial engineer analyzes operator work, they are doing essentially what the Gilbreths did: breaking the task into individual motions, identifying which motions add value, and redesigning the workstation and work method to eliminate the ones that do not.
How to Recognize Motion Waste
- Operators walking away from their workstation to get parts or tools
- Reaching across a wide workbench or up to high shelves
- Bending down to pick up parts from floor-level containers
- Turning around to access equipment behind them
- Searching for tools, fixtures, or gauges not in their designated location
- Repeatedly shifting grip or repositioning parts before assembly
- Excessive hand and arm movements within the work cycle
- Walking between machines or processes during multiprocess handling
Countermeasures
Workstation layout redesign — Arrange all tools, parts, and fixtures within the operator’s natural reach envelope. Parts should be at waist height. Tools should hang from retractable balancers directly above the point of use. No reaching up, bending down, or turning around.
4S/5S — Sort, set in order, shine, standardize. Every tool has a designated location. Shadow boards make missing tools immediately visible. When everything is in its place, the operator never searches.
Standardized work — Define the optimal sequence of hand and body movements. Standardized work charts show not just what the operator does, but how they move through the cycle — the walking path, the reach pattern, the sequence of picks and places.
Chaku-chaku (load-load) cell design — In chaku-chaku cells, machines auto-eject completed parts. The operator’s only motions are: pick up part → load into machine → walk to next machine → pick up part → load into machine. All non-value-adding motions (unloading, inspecting, adjusting) are eliminated or automated.
Right-sizing containers — Use smaller containers that bring parts closer to the point of use. Large bins on the floor force bending; small containers on angled racks at waist height eliminate bending entirely.
Ergonomic analysis — Study the operator’s physical movements for strain, awkward postures, and repetitive stress. Motion waste is not only unproductive — excessive or awkward motion causes injury. Toyota’s ergonomic standards directly reduce motion waste while protecting worker health.
Common Mistakes
Confusing motion with transport. Motion is the movement of people; transport is the movement of materials. An operator walking to a storage area is motion waste. A forklift moving pallets between buildings is transport waste. The distinction matters because the countermeasures differ: motion waste is solved at the workstation level, transport waste at the layout level.
Accepting motion waste because the operator is “busy.” An operator who is constantly moving — walking, reaching, searching — appears active and productive. But if those movements do not transform the product, they are waste. The operator who stands in one spot and performs value-adding work with minimal movement is more productive than the operator who hustles around the workstation.
Ignoring motion waste in office and knowledge work. Walking to a printer, searching for files, navigating between software applications, scrolling through emails — these are the knowledge-work equivalents of searching for tools and walking to storage areas. The Gilbreth framework applies to any human activity, not just manufacturing.
Optimizing individual motions without redesigning the workstation. Training operators to move faster or more efficiently within a poor layout has limited impact. The fundamental countermeasure is redesigning the workstation so that unnecessary motions are physically eliminated — parts arrive at the right height, tools are overhead, the work sequence flows naturally from left to right (or right to left) without backtracking.