Fred Brooks adage: "adding manpower to a late software project makes it later"

Fred Brooks' adage about software projects (known as Brooks' law) states, "adding manpower to a late software project makes it later". He explains the problem in terms of the communication overhead in a group. For example as the number of people involved in a project grows, the communication overhead grows faster. The overhead grows so fast that projects quickly become unmanageable.

Can you identify the errors in the diagram?

For a group of 'n' people, which of the following might be suitable functions to use to model this behaviour. What assumptions would you need to make to justify your choice?

f(n): n

f(n): n-1

f(n): n+1

f(n): n-m

f(n): n^2

f(n): n^2/2

f(n): n(n-1)

f(n): n(n+1)

f(n): n(n^2)

f(n): n(n+1)/2

f(n): n(n-1)/2