I read manual about COSMIC, but I have not found formula to convert from CFP to effort (person-month) yet. Can you introduce some document to do it (especially for CFP), or I use COCOMO… to estimate effort from CFP?
Estimating effort from functional size is a scientific subject in itself, about which a lot of documentation is available. I can recommend the 2015 book written by prof. Alain Abran, called “Software Project Estimation” (see wiley.com).
The best way is to build an estimation model from data from your own organization. If you don’t have that, you can use data from the ISBSG-database or use commercial tools like SEER that take into account environment and risk factors.