resource estimation for a software development project

Usually, I give stage ratings for each artist and each resource with the percentage of their employment, then I give the final overall rating. For example, the implementation phase of a small project may require the participation of an architect (50% of his time), an analyst (25%), an infrastructure maintainer (10%), and three full-time developers. The phase lasts 6 weeks (30 working days), so the architect will be busy for 15 days, the analyst for 7, the administrator for 3, and each of the developers for all 30 days. Based on these labor costs, you can calculate the personnel costs. For the same 30 days, the team needs a task tracking system, a version control system, a couple of virtual machines for testing, a virtual machine with a deployed DBMS, and something else specific to the project. In addition, you need a license to use a cryptographic provider, certificates and containers of private keys for each stand and personally for each developer, so that you can use a digital signature.

Having such an assessment for each stage, it is easy to understand at what point we should hire or release a particular specialist, when and for how long we should order the necessary virtual machine for the project or purchase / rent equipment, when and for how long we need to obtain licenses for required third-party software, etc.