The goal of a time estimator is to find the elapsed telescope time ( ) needed to obtain a given rms noise, while a sensitivity estimator aims at finding the rms noise obtained when observing during .
The time needed 1) to do calibrations (e.g. pointing, focus, skydip) and 2) to slew the telescope between on-source integrations have to be added to to get the elapsed telescope time. The observing procedures to use MAMBO are standardized. This enables to decompose the telescope time into a succession of calibrations, scans and subscans, which will be close to the actual observing setup. We nevertheless include an additional efficiency factor ( ), which will take into account the possibility of bad weather and/or technical problems. The idea is that on average the PIs will reach their scientific goals, including possible hazards.