Key takeaways
- Lean identifies eight wastes, summarised by the acronym DOWNTIME.
- Waste is any activity that consumes resources without adding value the customer pays for.
- Several wastes (waiting, defects, excess processing) overlap directly with the six big losses and OEE.
- Seeing waste is the first step; the goal is to design it out, not just work around it.
Lean manufacturing defines waste as any activity that uses resources without adding value the customer would pay for. There are eight classic wastes, easy to remember with the acronym DOWNTIME. Learning to see them on your own floor is the first step to removing them.
The 8 wastes: DOWNTIME
Each letter is a type of waste:
- D - Defects: scrap and rework, the Quality side of OEE. Costs material, time and trust.
- O - Overproduction: making more or sooner than needed, which hides other problems and ties up cash.
- W - Waiting: idle people or machines waiting for material, instructions or the previous step. A direct availability loss.
- N - Non-utilised talent: not using the knowledge and ideas of the people who do the work.
- T - Transport: unnecessary movement of material between steps and stores.
- I - Inventory: excess raw, WIP or finished stock that hides problems and costs money to hold.
- M - Motion: unnecessary movement of people (hunting for tools, reaching, walking).
- E - Excess processing: doing more than the customer needs (over-tight tolerances, extra steps, double handling).
How the wastes overlap with OEE
Several wastes map straight onto the six big losses and OEE. Waiting is an availability loss. Defects and excess processing hit quality and performance. Overproduction often masks a slow or unreliable process. So removing waste and improving OEE are usually the same fight from two angles.
How to see and remove waste
Go and look (gemba). Walk the process, follow one part, and ask at each step whether it adds value the customer pays for. Map it, tag the wastes, and tackle the biggest first. Many wastes (waiting, motion, transport) are designed in by layout and scheduling, so the durable fix is to redesign the flow, not just to ask people to hurry.
Waiting and micro-stops are often the hardest waste to see because they are short and unlogged. The partner we recommend, Fabrico, captures them automatically with their true cause. Fabrico is a partner we recommend; the tools here are free regardless.
Size the prize with the free OEE and downtime calculators.
FAQ
What are the 8 wastes of lean?
Defects, Overproduction, Waiting, Non-utilised talent, Transport, Inventory, Motion and Excess processing, remembered by the acronym DOWNTIME.
What is the DOWNTIME acronym?
DOWNTIME stands for Defects, Overproduction, Waiting, Non-utilised talent, Transport, Inventory, Motion, Excess processing, the eight wastes of lean.
How do the 8 wastes relate to OEE?
Several map directly onto OEE: waiting is an availability loss, defects and excess processing hit quality and performance. Removing waste and raising OEE are largely the same work.
Related: the six big losses · what is OEE · micro-stops & the hidden factory · SMED & changeover