Lear · Body 2 · 31XX-2 · measured 25 August 2026 · 18:00–20:00 UTC
Work content, board by board
The bar chart on the work-content page shows each station's average and
says the problem is the spread. This is the spread. Same measurement, same twelve stations —
cut into the 40 board cycles the two hours actually contain, instead of averaged flat.
Every station, every board
person-minutes of hands-on work · one cell = one board cycle (179 s)
18:00 UTC — first hour
19:00 UTC — second hour
less workmore work cycle exceeds 5.97 p-min▨ no data
What the eye should catch first. B2C5 runs hot through the
first hour — including the single heaviest cycle measured anywhere on the line, 9.70 p-min — and then
goes cold for the whole second hour. B2C8 does the same, less sharply. Those two stations account for
89% of the line's entire second-hour drop; the other nine are flat. That is a
staffing event at two stations, not the line slowing down.
The spread, not the average
box = p10–p90 of cycles · line = full range · dot = mean, the number on the current chart
This is the drop-in change. The existing chart plots the black
dot alone. Adding the box and the range says the thing the page already asserts in prose: B2C14's
average of 5.55 sits just under the 5.97 line, but its cycles run to 7.96 — it is over capacity on a
large minority of boards. B2C5 swings 8.3× between its quietest and busiest cycle.
As it happens
each station's own trace · horizontal rule = 5.97 p-min · shaded = second hour
Before this is shown to anyone
what the chart can and cannot carry
The fluctuation is real, not sampling noise. Engagement is sampled every 15 s,
so a cycle holds only 12 samples and some spread is inevitable. Shuffling each station's samples in
time gives the noise floor: 56–87% of the observed cycle-to-cycle spread survives it,
varying by station. The traces are signal.
The 5.97 line is assumed, not measured. It is 2 operators × 179 s ÷ 60. Measured
presence averages 1.62 people per station and ranges from 0.89 at B2C12 to 2.50 at
B2C14, so a single flat line fits no station exactly and is generous to the light ones. Treat it as a
reference, not a capacity. Asking Lear for actual manning per station would replace the weakest
number in both charts.
Cycle boundaries are approximate. Cells are fixed 180 s windows from the clip
start, against a true pitch of 179 s — they are not phase-locked to real board arrivals, and drift
about one cycle-width across the two hours. Fine for "how much did this station swing", wrong for
"which board was heavy".
Two stations are short. B2C14 has no second-hour clip (18 of 40 cycles) and
B2C7's first-hour clip ends early (29 of 40). Missing cycles are hatched, never zero-filled.
B2C11 views a walkway and its numbers are flagged throughout the study. It is
shown here for completeness, not for use.