Encumbrance

Recall that class B is a provider of class A if A references B:

Providers(A) = { B | A references B }

We can also study the transitive closure of this set:

Providers^*(A) = { B | A depends on B }

The size of this set is called the encumbrance of A:

encumbance(A) = #Providers^*(A)

If A is to be reused in another program, then its encumbrance tells us how many other classes will need to be added to the program to make A work.

Example

Compute encumbrance(A) where:

providers(A) = {B, C}

providers*(A) = {A, B, C, D, E}

encumbrance(A) = #providers*(A) = 5