The team did give us an idea some years back, I think shortly after Cats and Dogs came out. If I remember right, they said:
*EPs can take anywhere from 1 to 3, sometimes even more years to develop. Cats and Dogs took over 3 years because it is one of the most complicated EPs to make, and is essentially creating brand new "Sims" from scratch.
*GPs take on average 5 or 6 months, up to a year.
*SPs take around 3 months, but the community SPs took much longer due to voting and info sharing.
** Of course, these were just averages at the time but we were also told that it can vary. Sometimes devs can be pulled off one project to assist with another if the deadline is approaching or the project is falling behind. They also said that they always have multiple projects in production at once, some assets take much longer than others, and they usually have to plan way ahead for themes, schedules and release dates. It should also be noted that when they said this, we were not in the middle of a pandemic and they were still working in the dev offices at full convenience so working from home could have completely altered how they function now.
