2026-03-12
Name the stop before you total the hours
Most shift boards in discrete plants still treat downtime as a single column. The supervisor writes a number at the end of the shift, sometimes after arguing with the count from packing. That number is not false. It is incomplete. When we later ask why Thursday lost two hours, the crew remembers a jammed nest, a missing carton lot, and a quality hold that lasted through break. None of those share a cause, and none of them will move if the only action is “call maintenance more often.”
Before totaling hours, agree a short dictionary at the line. Five to eight names is enough: starved by upstream, blocked by downstream, changeover, quality hold, jam or reset, waiting on material, waiting on a person, and planned meeting or break if those are still being mixed into lost time. Operators should be able to point at a physical place when they say the name. If “jam” can mean both a sensor dirty from oil mist and a pallet that was never staged, split it.
Write the names on the board in the same order every day. When a stop happens, the nearest person ticks a tally, not a duration guess. Durations come from the clock at restart, or from a simple start/stop mark on a card. Guessed minutes inflate the dramatic stops and hide the small waits that actually eat the shift.
A throughput study that skips this dictionary will still produce a chart. The chart will look decisive and will point at the wrong station. The cheaper work is standing at the board on Monday morning and arguing, politely, about what the words mean.