The big builders like DR Horton and Lennar target build times of 100 days per home that meets minimum code requirements, which is pretty good productivity. A community of 100 homes can be up and running in 2 years.
And that 100 days target is mainly for achieving optimal efficiency. If you want to optimize for time it's totally possible to go from an empty lot to a finished house in under a week, provided that all the workers, inspectors, and materials are available.
Requires a ton of overhead at the planning / pre-construction phases. That’s only amortized out if you built a ton of volume which these do. It’s also why you may only have a choice of 8 floor plans even though it’s a neighborhood of 500 homes.
