Journal
What a Pareto of stop reasons usually hides
A ranked chart of stop hours by code is useful only if the codes mean the same thing on Monday and on Thursday. In plants we visit, ‘jam’, ‘quality’, and ‘waiting’ frequently describe the same event from three chairs: the operator, the inspector, and the forklift driver. Adding those bars as if they were independent inflates the middle of the chart and shrinks the real constraint.
Read the comments, not only the codes. A hundred ‘waiting’ events that all mention the same wrapping film tell a different story from a hundred waits for different materials. We group comments by noun — film, pallets, labels, a named machine — before we trust the ranking.
Short stops under a minute often never reach the book. If the line stutters every few packs, the Pareto of written stops will look calm while the first-hour counts look poor. Pair the chart with a spell of timed observation. The missing minutes are not a rounding error; they are the difference between a line that ‘runs’ and a line that earns its rate.
Treat ‘other’ as a warning, not a category. When it sits in the top three, the coding list is too coarse or too long. A factory manager can ask for a fortnight of comments only, then rebuild five codes that people will actually use at 2 a.m.