The Oversight Ministry reduces the amount of time buildings take to upgrade through better project management. All buildings will be built/upgraded 3% faster per level of the Oversight Ministry. Like most building except the university and genetics lab, the effect only takes place on the planet which the Oversight Ministry is built on.
Keywords: Construction Buildings
Each level of the OM subtracts 3% from the 'absolute build time' which is what I refer to as the time it would take to build if there were no OM on the planet. So, with an OM at level 30, the build time is 10x the absolute build time.
To validate this, I used the get_stats_for_level API to grab the upgrade time for a L10 Development Ministry on 2 different planets: one with L9 OM and one with L7 OM. The L9 planet gave an upgrade time of 27769s and the L7 planet gave an upgrade time of 30052s. If I plug these numbers into the equation above:
L9 -> 27769/(1-(.03*9)) = 38040
L7 -> 30052/(1-(.03*7)) = 38040
Since they are equal, you can conclude that the absolute build time of a L10 Dev Min is 38040s.
These numbers are *ONLY* valid for a specific set of species affinities. If your affinities change, then you will need to recapture the get_stats_for_level data and recalculate the absolute build times.
The OM cuts down build time by 3% per OM level.
I advise changing the description to that because "faster" is vague, as discussed in the previous comments."