Working on the project plan and WBS during engagement phases, sales usually want to provide features to the client so that he can pick and choose. It is easy to do it in excel with % and so on... But in reality for example in MS Project, it is simpler to form work packages (features) based on engineers estimate but put aside project management and business analysis services (e.g. 1 BA and 50% PM for the entire project duration).
In this case I can still plan the schedule and the total efforts, but work packages do not include management services/ba services, hence the cost is not correct.
Putting management and BA into every work package is not easy as work packages may go in parallel (2 or 3 or 4), so splitting management and ba efforts between would be tedious.
What I want is to have work package cost with all the work included and I don't want to put management and BA into work package and then have leveling issues.
How do you usually solve such a challenge?