SELF-CHECK
A takes 2 days; B takes 4 after A; C takes 3 after A; D takes 1 after B and C. What is the minimum modeled duration?

REFERENCE REASONING
A-B-D takes 7 days and A-C-D takes 6. With these assumptions the minimum is 7 days and C has 1 day of total float.

This is a reasoning reference for the supplied fictional case, not an executed app or tested cloud deployment. Alternative approaches are valid when supported by stated assumptions and evidence.
