In terms of the project management scope of work and work flow, the concept of reserve analysis actually refers to a specific technique that is often implemented by the project management team and/or the project management team leader or leaders for the purposes of helping to better maintain and manage the projects that they may have under their guise at that respective time.
Specifically speaking, the technique of reserve analysis is a particular analytical technique that is used for the purposes of making a complete and thorough determination of the entirety of the specific and exact features and or in many cases relationships of all of the individual project related components that currently exist as part of the previously determined project management plan. The purpose of the execution and implementation of a reserve analysis is the establishment of an estimated reserve that can be used for the purposes of establishing a schedule duration, any and all estimated costs, the budget, as well as the complete funds assigned or allocated to the project.
This term is defined in the 3rd and the 4th edition of the PMBOK.