Would Brooks' Law apply to cost?

 

When Fred Brooks Jr. wrote The Mythical Man Month, he provided project managers with the valuable caution which later was named Brooks' Law: "Adding manpower to a late software project makes it later".

While there are always exceptions, this statement is generally true. It is also applicable to most types of projects, not just software development ones.

The supporting reasons for Brooks' Law are well understood but unfortunately forgotten by project managers and senior stakeholders when delays occur.

Procuring and onboarding new team members will distract existing ones who should be focused on completing critical activities. It also requires more effort to keep everyone on the team aligned and increases the risk of personal conflict or other interpersonal sources of delay when we have more team members. And, if the majority of the remaining activities are not effort-driven, adding people won't help to accelerate them.

But does the complementary hypothesis of adding funds to a project which is forecast as completing over budget will make it go even more over budget also hold true?

Similar to Brooks' Law where it won't apply if the project was under staffed to begin with, an exception would be if the project had an inadequate budget to start with as a result of under estimation, under funding or insufficient contingency reserves.

But when a project received sufficient funding to deliver the original approved scope why might addressing a negative cost variance by boosting the budget be the wrong thing to do?

If the variance relates to under performance, low productivity or a high cost of poor quality, then adding more funds to the budget might encourage more of the same and the variance is likely to increase. If the variance is caused by scope creep, then providing more funding might result in it being used as a slush fund by stakeholders for getting additional scope.

The forecast at completion might also be suspect. If a forecasting assumption is that historical performance will persist, is that supported by the risk profile of the remaining activities? If things are expected to get easier then adding funding will just generate unnecessary opportunity costs for the organization.

Sponsors and senior stakeholders usually tend to be more open to adding people rather than funding for troubled projects which is why this situation is less common, but when it does, we need to understand why the cost variance occurred and also how the forecast at completion was determined.