This site has a detailed thread that explains MIPS and related issues:
My handy shortcuts for capacity planning :
One MSU = 6 Mips (here MSU and Mips represent a consumption speed, not an accumulated consumption). So a job that constantly uses 10 MSU (as displayed by monitors) uses 60 Mips.
To convert CPU seconds (accumulated consumption) to Mips (average consumption speed): Mips = (CPU seconds)*EUM/(Elapsed seconds) where EUM=EQUIVALENT UNIPROCESSOR MIPS as defined in the REXX exec below. Example: a job has used 100 CPU seconds during 1 minute (it is a multi-task job). The system is a 2064-1C5 (1085 MIPS, EUM=217 MIPS). The average consumption speed of this job is 100*217/60=362 MIPS.