Ranking Theorem requires two assumptions, which are both violated in this context: 1) The projects are independent 2) Not all project need completion to achieve success (i.e. you can select a subset of projects)

Here, the failure of one part leads to the failure of the whole project, and all parts of a project need completion at some point in time. The task at hand is thus to select the order of parts of projects to maximize the overall gain over many projects.