The “slope of ineffective efficacy” is at a point just after the bulk of the planning process is completed, and after the “implement” order from required managers has been achieved. It is at this point at which one can bring in that throng of “must have buy in” mid-level managers with the most positive and least negative impact.
It’s too late for them to scuttle the project politically in the planning stages.
It’s too early for them to claim it’s somebody else’s project, and scuttle it because one is not getting any credit. In fact it’s just in time for them to claim credit themselves, which is critical.
Most important, it’s too late to scuttle the project by “adding value.”
During the period in a project life-cycle I term the “slope of ineffective efficacy,” mid-level managers can be brought on board, claim some ownership, not have any direct hands-on impact, and they can benefit themselves by gloaming onto the success, while not really being in a position to try and kill the project.