Project Management: Foundations to Practice · Schedule Management and the Critical Path Method
Sequencing Activities and Dependencies
Getting dependency types right is the invisible groundwork beneath every schedule that later looks impossible to execute. This chapter covers the four types and why finish-to-start dominates most real schedules.
Before a schedule can be built, project activities must be sequenced according to their dependencies. The four common dependency types are finish-to-start, where one activity cannot begin until another finishes; start-to-start, where two activities must begin together; finish-to-finish, where two activities must end together; and start-to-finish, the least common, where one activity cannot finish until another begins [1].
Key Takeaways
- The four dependency types are finish-to-start, start-to-start, finish-to-finish, and start-to-finish (the rarest).
- Finish-to-start dominates real schedules because most work genuinely cannot start until a prerequisite is complete.
- Correctly identifying start-to-start or finish-to-finish dependencies can reveal genuine opportunities for parallel work and compression.
- Misrepresenting a real dependency as independent produces a schedule that is impossible to execute, regardless of effort applied.