Lesson 4 of 23 · 7 min read
Errors, work nobody uses, more than needed, skills not used
In Lean: the other four wastes: defects, overproduction, extra-processing, non-utilised talent
Builds on: Waiting, Handoffs, Backlog, Searching and switching
In one minute
The other four wastes are about effort: Errors and rework, Work nobody uses, Extra steps, and Skills not used. They are harder to spot than a queue, because everyone involved is busy and often working hard. Most real frictions show more than one waste, so this lesson also shows how to pick the primary one: the waste whose cause, if fixed, would make most of the rest disappear.
The idea
Errors and rework (in Lean: defects)
Something was wrong or incomplete, so it has to be corrected: a payroll change entered wrongly, a request sent back for missing details, a report rebuilt because the source data disagrees. The cost is more than the fix. It includes finding the error, everyone downstream who acted on it, and the extra checks added afterwards because trust was lost. Errors are best stopped where they start, not where they are found.
Work nobody uses (in Lean: overproduction)
Output that nobody needs, or that is made earlier or in greater quantity than anyone needs it: the weekly report nobody opens, a custom proposal for every prospect before anyone is qualified, a plan detailed months ahead and redone when priorities change. Lean treats this as an especially harmful waste because it creates others: what is produced must then be stored, sent, checked and kept up to date.
Extra steps (in Lean: extra-processing)
The output is used, but more effort goes into it than its purpose needs: a third approval that has never changed a decision, a check that never finds anything, polish nobody asked for, the same data typed into a second system. The test that separates it from Work nobody uses: is the output used? If nobody uses it, it is Work nobody uses. If it is used but costs more than it should, it is Extra steps. Some Lean writers call this over-processing.
Skills not used (in Lean: non-utilised talent)
People spend their time on work that does not need what they know, or have ideas with nowhere to go: a qualified accountant keying receipts, senior engineers resetting passwords, a team that sees the same problem every week and has no way to change it. This waste was added to the original seven by later Lean practice, outside Toyota. It describes how work is assigned and designed, never a person being "overqualified".
Primary and secondary
Real frictions rarely show only one waste. Pick as primary the waste whose cause, if fixed, would make most of the rest disappear. A secondary is a second waste that is genuinely present, not just a consequence you could also name.
Take a purchase that needs three sign-offs, the last of which has never refused anything. Everyone feels the Waiting. But the cause is a sign-off that adds no check, so the primary is Extra steps: remove it and most of the wait goes with it. Waiting is a fair secondary. When a waste is suggested for one of your frictions, use this test to decide whether you agree.
Example
Illustrative example, not a real company.
A marketing analyst builds a monthly campaign report. Every month she spends most of a day correcting campaign tags, because each person who sets up a campaign names them their own way (Errors and rework). The report then goes through two reviews that only ever change formatting (Extra steps). Readers look at the summary page and rarely at the pages behind it (Work nobody uses). She was hired to build forecasts and has little time left for them (Skills not used).
She reports the monthly tag correction. Fix its cause, a shared naming rule for campaign tags, and the rework goes and her time comes back. So the primary is Errors and rework, and Skills not used is a fair secondary. The extra reviews and the unread pages are real too; each deserves a friction of its own.
Common mistakes
- Calling unused output Extra steps. If nobody uses it, it is Work nobody uses, however polished it is.
- Naming the symptom instead of the cause. A two-day reconciliation feels like effort, but the waste is often the wrong data that makes reconciling necessary.
- Reading Skills not used as a complaint about people. It describes how work is assigned.
Words to know
- Errors and rework (in Lean: defects): correcting what was wrong or incomplete.
- Work nobody uses (in Lean: overproduction): output with no user, or made too early or too much.
- Extra steps (in Lean: extra-processing): more effort on used work than it needs.
- Skills not used (in Lean: non-utilised talent): people's knowledge and ideas left unused.
- Main waste and second waste (often called primary and secondary waste): a working convention for classifying a friction, not a classic Lean term.
Check your understanding
Try it on your own work
Describe one recurring task that wastes your time, and see these ideas applied to it.
Worksheet for this lesson: 8 Wastes Checklist (free download, no sign-up).
Where this comes from
Defects, overproduction and over-processing are among the seven wastes of the Toyota Production System; unused talent was added later by Lean practitioners outside Toyota, and all eight were then carried into service and office work.