Didn't fly big machinery, but a tale of small twin turbine. In cruise and oil pressure dropped into the yellow and temp reduction of 10°. Reduced power to idle and pressure was in the bottom of allowable. No APU, kept engine running so as to have auxiliaries available, and should our "good" engine decide to take a holiday. Upon landing and shutting down ramp advised of a puddle of oil on the tarmac. Checking the dipstick no oil was evident. Cause, a split in the reservoir to pump line. So while the engine was running it was sucking in air and aerating the oil, explaining the drop in both pressure and temp. The instant of shutting down all the oil drained out of the split.
Earlier in life had been given the advice, "never shut down an engine capable of providing power".