The lean methodology defines 8 forms of waste:

  1. Transportation
  2. Inventory
  3. Motion
  4. Waiting
  5. Over-processing
  6. Overproduction
  7. Defects
  8. Skills underutilized

Originally, seven wastes (Muda) were developed by Taiichi Ohno, the Chief Engineer at Toyota, as part of the Toyota Production System (TPS). The seven wastes were Transportation, Inventory, Motion, Waiting, Over-processing, Overproduction, and Defects. They are often referred to by the acronym ‘TIMWOOD’. The 8th waste of underutilized talent or ‘Skills’ of workers was later introduced in the 1990s when the Toyota Production System was adopted in the Western world. As a result, the 8 wastes are commonly referred to as ‘TIMWOODS’. Here are all wastes in detail:

Transportation waste

Unnecessary movement of materials or people within a process, etc. that adds unnecessary time to the flow, increasing the risk of being lost, placed in the wrong location during transportation.

  • Can cause production delays, handling damage, time for transportation is not contributing to output.
  • Long transportation impacts communication, resulting in delays and this can also affect product quality.

How to reduce transportation?

  • Challenge the current layout and try to minimize the transportation of material from one function to another.

Inventory waste

Packaging or finished goods (FG) inventory, requires extra storage space and handling, raw materials not being processed.

  • Work in process (WIP) stored to reduce time to complete new orders, FG waiting for packaging, defective product waiting for rework…

Inventory’s Dark Side:

  • Often a symptom of problems in the process that are hidden behind rising stock levels.
  • Increases operational costs, including conveyance, storage, risk of obsolescence.
  • Increases production lead time.

How to reduce inventory?

  • Define necessary inventory levels and minimize by reducing batch sizes in production and limiting WIP.

Motion waste

Excessive turning, lifting, walking – all unnecessary motions that increase process time. Unnecessary movement of people or machines within a process.

How to reduce wasted motion?

  • Check: do manual and machine work cycles contain unnecessary motion elements?
  • Check: are the tooling, equipment and parts around work stations optimized?
  • Check: is the layout optimized for varying customer demands?

Waiting waste

Failures of upstream process, creating idle time in the current step, causing issues with the downstream process. People or machines waiting for the completion of a work cycle.

How to reduce waiting?

  • Check: does the machine need to be monitored? Are there built-in checks to stop the machine from producing defective products?
  • Check: is the production line balanced so that people and machines have minimal idle time?
  • Check: can idle time be filled in other ways? (quality checks, cleaning, material handling….)

Over-processing waste

Operation or process not required to meet customer demand as well contains additional features that are not required by the customer.

  • Over-processing often happens when standards are difficult to define (polishing, painting, etc.).

How to reduce over-processing?

  • Clear understanding of the customer’s expectations and correct translation into specifications, which are then followed by design and production.

Overproduction waste

Finished Goods are ready before customer needs them, occupying resources and considered one of the worst losses. Producing sooner, faster, or in greater quantities than customer demand.

  • Over-produced items end up as inventory or scrap, therefore creating other waste.
  • Overproduction takes time away from value-added activities.

How to reduce overproduction?

  • Clear understanding of the customer demand and produce only what the customer wants, and when it is needed.

Defects waste

Rework generated due to damaged packaging, bad date code, or best before on FG, a product that was put on hold due to quality issues, resulting in lost sales or hidden costs. Producing product that does not meet specifications.

  • Causes of defects: methods, materials, machines, manpower, environment

How to reduce defects?

  • Improve process capability by analyzing and solving the root causes of the defects

Skills underutilized waste

  • Shop floor talent that is not used properly, causing lower employee morale, drive and creativity.

Gemba Waste Walk Template

We just talked about 8 sources of waste. Would you like to identify these at your manufacturing facility? Use our template while walking all areas, observe and note so it can be analyzed and actioned later on.

Template to identify 8 wastes on production floor

A printable template can be downloaded here

Exercise:

  • Create presentation using training materials from this lesson
  • Invite team members for a meeting
  • Present the knowledge
  • Explain how to use the form
  • Go to Gemba (actual place, for example production floor)
  • Walk through all accessible areas and observe all wastes described in the form
  • Note all wastes
  • Return to the room and review findings
  • Brainstorm and come up with ideas how to reduce/eliminate wastes

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