Scope, schedules, resources and project dependencies

Plan deliverables and their dependencies

State the project’s intended outputs, included work and completion criteria. Break the work into activities at a level useful for assignment and evidence. Include integration, review, enabling equipment and external deliveries where they are necessary; a schedule omitting those activities can underestimate the route to a usable result.

A dependency describes which event or result another activity requires. An activity’s duration is elapsed scheduled working time, while effort is the amount of work supplied by people or equipment. A task requiring several person-days does not automatically take one elapsed day when more people are assigned; coordination, sequence and available facilities can limit parallel work.

Find the driving route under stated assumptions

Our original model assigns A: scope definition 2 days. After A, B: build 4 days and C: records 3 days can run in parallel. D: integrated trial 2 days begins only after both finish. Assume one working calendar, finish-to-start relationships, fixed nonpreemptive durations and sufficient independent resources. A ends at 2, B at 6, C at 5 and D at 8.

The A–B–D path totals 8 days; A–C–D totals 7. C can move one day later without delaying the earliest project finish in this simple model. That is its total float here. The path and float depend on the supplied logic and durations; they are not permanent labels attached to a type of work.

A valid route still needs available capacity

Suppose B and C instead require the same exclusive specialist throughout each activity. They cannot overlap. With the same durations and no other constraints, either sequential order makes the earliest finish 2+4+3+2=11 days. The dependency-only eight-day diagram was insufficient for that resource arrangement.

Update actual progress, remaining work and changed dependencies with their dates and reasons. A completed activity, new risk or delayed external input can change the driving route. Keep the agreed baseline and current forecast distinguishable. Uncertainty in durations and correlated delays require an explicit account; adding all “most likely” durations does not establish a promised completion probability.

Check what shortening a task can achieve

In the independent-resource model, reducing C from 3 to 2 days leaves B finishing at 6, so D still ends at 8. The project duration does not improve even though a task is shorter. Reducing B from 4 to 3 makes both branches finish at 5 and D end at 7. Both branches then matter to the finish.

If the shared-resource condition applies, shortening C by one day instead reduces the sequential total from 11 to 10. The same local change has a different project effect because the resource model differs. Check the actual logic, scope and availability before promising that a faster task will deliver an earlier project.

Try the reasoning

1. Does a logical absence of dependency guarantee tasks can overlap?

   Show the answer and reasoning

   No. They can still compete for people, equipment, space or another exclusive resource.

2. Why does shortening C alone fail to improve the original eight-day model?

   Show the answer and reasoning

   B still controls the start of D under those supplied dependencies and independent resources.

3. What should a schedule update preserve?

   Show the answer and reasoning

   The actual progress and revised assumptions, their reasons and dates, and the distinction from the agreed baseline.

What to carry forward

Build the schedule from required work and dependencies, then verify that its parallel activities have the resources and evidence needed to occur.