PS-LOD-102 · r4
WORKLOAD
OBSERVED
ENGAGED
FATIGUE ACROSS LONG SHIFT
The display was settled in the first hour and is read in the ninth hour.
01 DEFINITION
Condition in which one surface is read by one person across a span long enough that what can be taken from it changes, so the display agreed at the start of a shift is not the display in effect at the end of it.
02 CONDITIONS
UNCERTAINTY
UNRECORDED
How much the reader has left is not known to the thing being read, and not to the reader either.
TIME PRESSURE
SUSTAINED
Nothing is urgent; the span itself is the condition.
ERROR ASYMMETRY
DEFERRED
What is missed late in a shift is paid for after the shift has ended.
OPERATOR STATE
DEDICATED
One person, one surface, for the length of the shift.
03 WHERE IT APPEARS
MEDICALA monitor read at the start of a shift and at its end is the same display and not the same account.
ENERGYA control room surface is settled in daylight and relied on through the night by people whose reading of it has shifted.
MANUFACTURINGLine-side indication designed for an alert operator is read by one at the end of a long run.
LOGISTICSA dispatch surface is worked continuously by people whose capacity to take from it falls across the span.
MOBILITYAn instrument arrangement is fixed at design time and read across journeys of very different length.
PUBLIC SERVICEA case-handling surface is used through a full day by people whose reading of it degrades without their noticing.
04 WHAT AEON WORKED THROUGH HERE
The same screen that was legible at the start of a night shift was not legible at the end of one, and nothing about it had changed. Adjusting it by hand meant the person least able to judge was the one judging. The work went into which parts of the account must hold still to stay trustworthy and which may follow the eye, so that the two were decided separately rather than together.
The question it keeps returning to is whether a surface should follow the person down — one that adapts as they tire is one they cannot trust to look the same twice, and one that holds still was settled for an hour that has passed.