Five questions to ask about your own operation
- 01Is rework built into your production schedule or your capacity plan?
- 02When did your defect rate last appear on a leadership agenda as an item of its own?
- 03Do you know what your defects cost each month, in pounds?
- 04Can your team name the top three defect types, in order, from data rather than memory?
- 05Has the process been tested to show whether it is capable of meeting the specification?
If rework is planned for and its cost is unknown, the loss has become part of the operation.
Why stable losses cost the most
A chronic defect rate is easy to live with. It is predictable, so schedules absorb it, and it is familiar, so nobody questions it. Over time the rework, the extra inspection and the scrap allowance become part of how the site runs, and the cost disappears into the standard.
The language changes too. People begin to describe the process as difficult or the product as complex. A rate that should prompt an investigation becomes a characteristic of the line.
What the recovery looked like
At an industrial equipment manufacturer, during a board-mandated turnaround, the defect rate on a production line stood at 32%. It was being managed as something the process did, rather than something wrong with it.
The work treated it as a measurable fault. Pareto analysis ranked the defect types so effort went where most of the loss sat. Control charts separated ordinary variation from specific causes, and capability studies showed whether the process could meet the specification at all. Causes were removed in order of size and controls were put in at source. The defect rate went from 32% to zero.
Read the full case, with the limits of its evidence →
What to check this week
- Put a monthly cost in pounds against your defect and rework rate, including labour and scrap.
- Rank last quarter’s defects by type and check whether the top three make up most of the total.
- Ask how long your current rate has been accepted as normal.
A loss that has been stable for a long time is usually stable because nobody has gone looking for its cause.