Review a project schedule from dependencies to a changed launch plan Skill Workbench · 2026-10-23 · Original fictional teaching material Trace a small dependency network, explain float and critical paths, then evaluate a changed plan before making a delivery commitment. Save a checked schedule-review portfolio. For a project coordinator who can add whole-day durations and read predecessor IDs. No scheduling software, account or coding is needed. - Calculate earliest start and finish times using the latest predecessor finish. - Distinguish total float from critical work and evaluate independent baseline changes. - Recompute a changed critical path and identify the resource confirmation needed before committing a date. CASE CONTRACT 1. Time is elapsed working days starting at 0. A task of duration 2 starting at 0 finishes at 2. No weekends or calendar dates are modeled. 2. All links are finish-to-start with zero lag. A task starts only when every predecessor has finished; parallel branches are allowed. 3. Assume unlimited parallel resources unless a question explicitly asks about the resource assumption. All durations are fixed fictional inputs, not estimates of a real team. 4. Use each unit’s own baseline. For alternative changes within a unit, change only the named duration and reset all other durations first. 5. A critical path is a longest start-to-finish dependency path in this fixed model. Total float is how much a task can slip without moving the model’s finish when other inputs stay fixed. 1. Trace the earliest possible finish Use the latest predecessor finish instead of adding every duration. A dependency is a condition for starting work, not merely a preferred order in a list. In this exercise a finish-to-start link means that the predecessor must finish before its successor begins. Write down the time boundary before doing arithmetic: elapsed day 0 is the start, and a two-day activity occupies the interval from 0 to 2. Counting both endpoints as whole extra days would create an off-by-one error. Move through the network from predecessors to successors. A task with no predecessor starts at 0. For any other task, take the largest finish time among its predecessors as its earliest start, then add its duration for its earliest finish. At a join, the later branch controls the start. Adding the branch finish times would wrongly treat parallel work as consecutive work. Elapsed duration and total effort are different measures. Two independent three-day tasks can run during the same three elapsed days if resources allow them to overlap. Adding every activity’s duration would instead describe a serial schedule. Here we deliberately ignore resource conflicts to isolate dependency arithmetic; that gives a clear model to inspect before introducing a real team’s staffing and calendars. Maintain an audit trail with task ID, predecessors, duration, earliest start and earliest finish. If a stakeholder disputes the completion time, you can point to the join that controls it rather than arguing from a picture. A schedule with a missing predecessor may look faster while omitting required work, so the calculation is useful only after the listed dependency assumptions are accepted. Worked example: a join waits for the later branch Task X finishes at day 4 and task Y at day 7. Z requires both and lasts 2 days. Its earliest start is max(4, 7) = 7 and its finish is 9. It does not start at 4 and it does not start at 11. This conclusion assumes X and Y can overlap without a resource conflict. Build a forward pass for this small network. Q and R are independent after P finishes. Small dependency network activity_id | activity | duration_days | predecessors P | Agree scope | 2 | Q | Build prototype | 3 | P R | Prepare test data | 4 | P S | Integrate | 2 | Q R YOUR EXERCISE Q earliest start (elapsed day): __________________ R earliest finish (elapsed day): __________________ S earliest start (elapsed day): __________________ Network finish (elapsed day): __________________ Which tasks may overlap in this model?: __________________ P Q: P and Q Q R: Q and R R S: R and S Your explanation: Explain why S starts at the later predecessor finish and name the staffing assumption that makes Q and R overlap possible. FEEDBACK AND WORKED SOLUTION P runs 0–2, Q 2–5, R 2–6 and S 6–8. Q and R overlap. R controls the join at S; this is an eight-day elapsed plan under unlimited parallel resources, not an eleven-day serial plan. Q earliest start (elapsed day) → 2. P finishes at day 2, so Q can start at 2. R earliest finish (elapsed day) → 6. R starts after P at 2 and takes 4 days: finish 6. S earliest start (elapsed day) → 6. Q finishes 5 and R finishes 6; S waits for max(5, 6). Network finish (elapsed day) → 8. S starts 6 and lasts 2 days: finish 8. Adding all four durations would wrongly give 11. Which tasks may overlap in this model? → Q and R. Q and R both depend only on P. P precedes Q, and S must wait for R. TRANSFER QUESTION If someone adds a required review between R and S, which predecessor and duration fields must change before you reuse the eight-day result? 2. Find float and test a launch proposal Explain which baseline branch controls launch and which changes consume slack. Now use the separate seven-activity rollout network. Perform the forward pass again and retain every finish time. The launch depends on release review and training, so its start waits for the later of those branches. A critical path is a longest dependency chain that drives the finish in this model; it is not simply the task with the longest individual duration or the highest management priority. To find total float, work backward from the baseline finish. The final task must finish by that boundary. For a predecessor with several successors, its latest allowed finish is the earliest latest-start among those successors. Subtract duration to find latest start, then subtract earliest start to get total float. This backward check helps distinguish a branch that can slip from one that immediately affects launch. Float is conditional, not a free allowance that every task can spend independently. If successive tasks share the same slack, delaying both can consume more than the branch has available. The questions below change one duration at a time from the baseline. Reset the network between alternatives; stacking unrelated changes would no longer test the proposal described in the label. A proposal to shorten noncritical training can reduce effort without moving the launch date. That may still have value, but it does not support an earlier delivery promise. Conversely, a delay on another branch may first consume float and only then move launch. Report both the revised finish and the reason, so a stakeholder can distinguish local task savings from an actual schedule gain. Worked example: a local saving may not move the finish A final one-day launch waits for review at day 10 and training at day 8. Launch finishes at 11. Cutting training to finish at 7 still leaves review controlling day 10, so finish remains 11. If training instead finishes at 12, the same join moves launch finish to 13. A fictional software rollout has seven activities. A stakeholder wants an earlier launch and proposes shortening training. First reconstruct the baseline dependency schedule, then evaluate a test-data delay and the proposed training reduction separately. Your deliverable is a schedule review with its critical path and a supported change recommendation. Rollout activities activity_id | activity | duration_days | predecessors A | Confirm requirements | 2 | B | Prototype | 3 | A C | Prepare test data | 2 | A D | Build and verify | 4 | B C E | Release review | 1 | D F | Prepare training | 3 | B G | Launch | 1 | E F YOUR EXERCISE Baseline launch finish (elapsed day): __________________ Baseline critical path: __________________ A B D E G: A → B → D → E → G A C D E G: A → C → D → E → G A B F G: A → B → F → G Total float for C (days): __________________ Total float for F (days): __________________ Launch finish if C takes two extra days: __________________ Launch finish if only F is one day shorter: __________________ Your explanation: Explain which proposal changes the launch date, identify the assumption most likely to need checking in a real team and give the resulting dates. The note is not automatically graded. FEEDBACK AND WORKED SOLUTION Earliest finish times are A=2, B=5, C=4, D=9, E=10, F=8 and G=11. The critical path is A-B-D-E-G. C has one day of float and F two. A two-day increase in C’s duration pushes launch to day 12; reducing F by one day leaves launch at day 11. Resource availability could change this simple model and needs a separate check. Baseline launch finish (elapsed day) → 11. A finishes 2; B 5; C 4; D starts max(5,4) and finishes 9; E finishes 10; F finishes 8; G finishes max(10,8)+1 = 11. Baseline critical path → A → B → D → E → G. The A-B-D-E-G path totals 2+3+4+1+1 = 11 days. The C branch totals 10 and the F branch totals 9. Total float for C (days) → 1. C can move from a day-2 start to day 3 and still finish by D’s baseline start at day 5. Total float for F (days) → 2. F normally finishes at day 8 but G waits until day 10 for E. F has two days of float. Launch finish if C takes two extra days → 12. C then finishes at day 6; D/E/G finish at 10/11/12. The first delay day uses C’s float, and the second moves launch. Launch finish if only F is one day shorter → 11. F would finish at day 7, but G still waits for E at day 10. Shortening this noncritical branch does not advance launch. TRANSFER QUESTION If two tasks on the same branch each claim the branch’s two days of float, what must be recalculated before accepting both slips? 3. Recompute a changed critical path before committing Evaluate a new duration baseline and compare two independent recovery ideas. The final unit replaces the baseline: preparing test data now takes five days. The table below is the new planning version, with all other durations and links retained. Recalculate from its inputs rather than adding a delay directly to the old finish. A previously shorter branch can become the controlling branch, changing which improvement would affect the date. First find the revised earliest times and a longest chain. Then evaluate two alternatives separately from that revised baseline: reduce B by one day, or reduce D by one day. An improvement to B can be absorbed by waiting for C, while a reduction to a controlling D can advance the final join. State which scenario a result belongs to; a list of dates without version labels is difficult to use safely. The one-day D reduction is a hypothetical duration input, not evidence that the work can actually be compressed. Before proposing it operationally, confirm an achievable method, available people and retained acceptance checks. A fixed network does not price acceleration, quantify risk or authorize dropping quality work. Report the calculated gain as conditional on those confirmations. Finally challenge the unlimited-resource assumption. If B and C need the same person and cannot overlap, the dependency-only result is insufficient even when every arithmetic answer is correct. Resource order, availability and calendars need to be added before a delivery commitment. Your handoff should name that missing confirmation rather than presenting the model’s finish as a guaranteed launch date. Worked example: recompute the join after changing a branch Two branches finish at 6 and 8 before a three-day task. The finish is 11. Shortening the day-6 branch by one day leaves 11 unchanged; shortening the three-day successor to two days makes it 10. This compares independent alternatives and assumes the shortened duration is feasible. This revised baseline has C=5 days. For the B and D alternatives, change exactly one duration by −1 day and reset the others to this revised table. Choose the conclusion for a possible shared B/C resource. Revised rollout baseline activity_id | activity | duration_days | predecessors A | Confirm requirements | 2 | B | Prototype | 3 | A C | Prepare test data | 5 | A D | Build and verify | 4 | B C E | Release review | 1 | D F | Prepare training | 3 | B G | Launch | 1 | E F YOUR EXERCISE Revised C earliest finish (elapsed day): __________________ Revised D earliest start (elapsed day): __________________ Revised baseline launch finish (elapsed day): __________________ Revised baseline critical path: __________________ A B D E G: A → B → D → E → G A C D E G: A → C → D → E → G A B F G: A → B → F → G Launch finish if only revised B is one day shorter: __________________ Launch finish if only revised D is one day shorter: __________________ If B and C need the same person and cannot overlap, what should the handoff say?: __________________ promise13: Promise day 13 because the dependency arithmetic passes. replan-resources: Confirm resource order and availability, then recalculate before committing. dropC: Drop C to preserve the date without further review. Your explanation: Write a change note identifying the C=5 baseline, its new critical path, both alternative finish days, and a resource/quality confirmation needed before committing to the shorter plan. FEEDBACK AND WORKED SOLUTION Revised baseline: A=2, B=5, C=7, D=11, E=12, F=8, G=13. Critical path A-C-D-E-G. Reducing B alone leaves finish 13; reducing D alone makes it 12. Verify D’s compression method and acceptance checks. If B/C share an exclusive person, plan their resource order and recalculate before a commitment. Revised C earliest finish (elapsed day) → 7. A finishes 2; C now takes 5 days and finishes 7. Revised D earliest start (elapsed day) → 7. D waits for B at 5 and C at 7, so starts 7. Revised baseline launch finish (elapsed day) → 13. D/E/G finish at 11/12/13; F finishes 8. Revised baseline critical path → A → C → D → E → G. The five-day C branch now controls D; A-C-D-E-G totals 13. Launch finish if only revised B is one day shorter → 13. B finishes 4 instead of 5, but D still waits for C at 7. Launch stays 13. Launch finish if only revised D is one day shorter → 12. D then finishes 10, E 11, and G 12. This assumes D can feasibly be shortened. If B and C need the same person and cannot overlap, what should the handoff say? → Confirm resource order and availability, then recalculate before committing.. The model assumed unlimited parallel resources. A shared exclusive person invalidates that assumption; the fixture does not specify a feasible resource schedule. TRANSFER QUESTION What would you ask to confirm before replacing a duration estimate with a shorter number in the schedule sent to the delivery team? PORTFOLIO REVIEW Keep all three exercise records and explanations. Fixed checks can be scored; explanations are ungraded. Do not infer occupational certification. SOURCE Microsoft Support: Manage your project’s critical path https://support.microsoft.com/en-us/project/manage-your-project-s-critical-path Background for the relationship between the finish-driving task sequence, float and a critical path that can change. The calculations here use an original simplified network, not Microsoft Project settings. O*NET 15-1299.09 task 16157 · 08/2019 · Monitor or track project milestones and deliverables. O*NET 15-1299.09 task 16170 · 08/2019 · Develop or update project plans for information technology projects including information such as project objectives, technologies, systems, information specifications, schedules, funding, and staffing. https://www.onetonline.org/link/summary/15-1299.09 O*NET 31.0, USDOL/ETA, CC BY 4.0. Skill Workbench authored the teaching and fictional practice; no endorsement.