Versions in Project Systems

Basically, there are different kinds of versions in PS.
They are as following:

1. Project versions - these are basically snapshots of a project at different stages of a project. Based on how the system is set up, a version could be created every time the system status of a project object is changed, for example. Or, we can manually create a project version in transaction CNS41 or the like. We can create a version with a key and then we could compare the different snapshots of a project against each other or against version 0 (operative project).

2. Simulation versions - these are essentially "play around with" versions. Meaning that we can use them to try "what if" kind of scenario by changing dates, structure, milestones, etc... and compare results with the operative version. For example, we may want to determine what the impact is going to be of a certain change to the project before making the actual change to the operative project. Then, we could create a simulation version, play around with it to make sure it does what we want it to do, then make the actual change to the operative change or we can convert the simulation version to the operative version also.The simulation version is a "play ground" for "what if" scenario for the project. The main difference between the project and simulation versions is that project versions cannot be changed/modified once they are copied, while simulation versions can be. Also, we cannot copy a project version to an operative version, but we can copy a simulation version to an operative version.

3. Planning/Controlling versions - these are the versions used for storing different kinds of planning details for the project. Essentially, these versions are also "operational" and can be changed as needed. For example, we may want to keep the operative version (version 0) always for actual costs, while we will use planning version P1 to store planned values from ECP, then version P2 for Unit Costing values, etc... Unlike simulation versions however, we cannot copy a planned version to the operational project. We can however, copy one plan version to the other.

4. Progress Versions - These versions are used for carrying out Earned Value Analysis and other measurements against project progress based on POC, etc.  Progress version is controlling area specific and defines the control data for POC and earned values. It is mandatory to maintain progress version along with method of calculation. The system records progress analysis data in the progress version. That is why we can get the result only if we maintain it in the progress tab of WBS.

Path in Customization:

SPRO -> Project System -> Progress-> Progress Analysis -> Define Measurement Method as Default.