MPN, I eventually had to get to grips with civil service reports. I was staggered to be given a 10 page document to report on my typist. She was brilliant and typed well above the maximum expected rate. She didn't want promotion just to be left in peace.
Later I mooted the idea that reports should be at the request of the individual with certain caveats.
If you had a career and wanted supporting reports
If your assignment was coming to an end so your poster could match to jobs
If your boss thought a report - good or bad - should be raised.
There was a story, many years ago when the Air Sec was in Adastral House, that a particular CS would file awkward files behind cabinets, under the carpet, or hidden somewhere when he didn't know what to do. Subjected often remainder in post for years undisturbed with the turbulence.