A Pareto of losses is a ranked view of downtime reasons — from the largest to the smallest — with a cumulative line showing how much of the total loss is covered. It is based on the Pareto principle: a small number of causes (often around 20%) account for most of the loss (often around 80%).
Why it is useful
Every factory has dozens of downtime reasons, and each has its own “advocate”. Pareto replaces gut feeling with a number: which reason to start with for the biggest effect. Instead of tackling five small problems at once, you tackle one big one.
Example
A hall with 6 machines, one month, 3,120 minutes of downtime in total:
| Reason | Minutes | Cumulative |
|---|---|---|
| Waiting for material | 1,050 | 34% |
| Tool change | 830 | 60% |
| Hydraulics | 420 | 74% |
| Quality check | 310 | 84% |
| No operator | 240 | 91% |
| Other 9 reasons | 270 | 100% |
The first two reasons are 60% of the loss. Neither is a “machine breakdown” — one is logistics, the other is setup. A new machine would not solve them. A better order sequence and a tool prepared before the changeover would.
How to read it
- Minutes, not number of cases. Ten stops of 1 minute are less than one of 40 minutes — unless you look at them as a performance loss.
- By machine and shift. A Pareto for the whole factory is a start; a Pareto for one machine in one shift is a place to act.
- Month after month. If the top reason falls, the second becomes the first. That is a sign the work is paying off.
- Watch “Other” and “Uncoded”. If they are in the top three, the data is not good enough for a decision — first sort out the list of reason codes.
Common mistakes
- A Pareto from memory. Without accurate data on every stop, Pareto shows the loud problems, not the biggest ones.
- Acting on all reasons at once. Energy is split and nothing shows up in the numbers.
- No re-check. After the action, look at the Pareto again — did it really fall?
In MachineTakt
Every coded stop goes into the losses by group and reason. The KPI screen shows them by machine, line, shift or period, and the same report is visible in the monthly overview — without Excel spreadsheets.