Observation Records
Two recorded checks are not three completed checks
A fictional round lists display stations A, B and C. A is recorded as on at 09:00, B has no observation, and C is recorded as off at 09:08. These labels describe only the supplied display state at each observation time. The example provides no expected on/off schedule, fault diagnosis or observation between those times.
01
Keep planned stations and observed entries separate
Start with the expected station list A, B and C. Attach the 09:00 on observation to A and the 09:08 off observation to C. Mark B not observed. Do not copy a previous value into B or classify it as off because there is no entry. The round has two observed stations out of three expected stations. That count describes coverage of this list, not equipment performance. A table can show every expected row even when one lacks a value, making the omission visible without inventing a measurement.
02
Separate a state from a judgement about that state
C being off at 09:08 does not establish a fault because no expected schedule is supplied. Likewise, A being on at 09:00 does not establish that it remained on afterward. Record those limits beside any summary. A useful sentence is: A was on at 09:00; C was off at 09:08; B was not observed. This is more precise than all stations checked or one station failed. If an expected state is later supplied, compare it explicitly with the timed observation rather than silently changing the original record.
03
Preserve the missing check when a later visit occurs
The reusable record contains round identifier, expected stations, observation times, observed states, missing entries, expected-state source and follow-up notes. If B is checked at 09:20, add that new observation with its own time. It can resolve the need for a later visit without proving what B showed at 09:00. Keep the original gap in the earlier round. This distinction makes the history useful to someone reviewing coverage later, while avoiding an apparent continuous record built from observations that occurred at different moments.