QSO 340 Module 4 Project Schedule and Critical Path Assignment example

Finding the Critical Path: Scheduling a Food Bank's Warehouse System Project Against a Holiday Deadline

[Student Name]

Southern New Hampshire University

QSO 340: Project Management

Module Four Assignment

[Instructor Name]

[Date]

The organization, setting and figures below are a composite written as a model document. No real employer, client, colleague or patient is described.

Finding the Critical Path: Scheduling a Food Bank's Warehouse System Project Against a Holiday Deadline

The Deadline

The composite Tri-River food bank must bring its new warehouse management system live by November 15, the end of the project's 37th week, because holiday food drives make late November through early January the worst possible time to change how the warehouses work. The project plan in Project One listed the work in its work breakdown structure but did not yet show whether the deadline was realistic. The critical path method, first described for industrial projects in the late 1950s (Kelley & Walker, 1959), answers that question by finding the longest chain of dependent work (Kerzner, 2022).

Activities, Durations and Dependencies

The project team broke the work packages into twelve activities and estimated each duration in weeks, based on the vendor's implementation plan and the food bank's staff availability. Requirements and process mapping (A, 5 weeks) comes first. Vendor contracting and system design (B, 6 weeks) and data cleanup (E, 6 weeks) follow A. System configuration (C, 12 weeks) and hardware installation, including scanners and freezer wireless coverage (D, 8 weeks), follow B. Trial data migrations (F, 4 weeks) need both C and E. Warehouse user testing (G, 4 weeks) needs C and D. The pantry pilot (H, 6 weeks) needs F and G. Warehouse staff training (I, 3 weeks) follows G. Pantry training (J, 4 weeks) follows H. Final migration and cutover (K, 1 week) needs I and J, and go-live support and handoff (L, 2 weeks) follows K.

Forward and Backward Pass

The forward pass calculates each activity's earliest start and finish, working from the beginning; the backward pass calculates the latest start and finish that would not delay the project, working back from the end. Float, the difference between the late and early start, shows how much an activity can slip without delaying the project. Table 1 summarizes the results in weeks from the project start.

Table 1

Critical Path Calculations, Warehouse Management System Project

Note. Composite estimates, in weeks from the project start. Zero float marks critical activities.

The Critical Path and the Float

The zero-float activities make up the critical path: A, B, C, then F and G in parallel, H, J, K and L. Because F and G have the same duration and both lead into the pilot, the network has two critical branches through that stage, which makes it more fragile: a delay in either the migrations or the warehouse testing delays everything after it. Data cleanup has 12 weeks of float and can be scheduled whenever the inventory analyst has time. Hardware has 4 weeks of float, and warehouse training has 7.

The critical path ends with cutover at week 38, one week after the week 37 deadline. The plan as estimated puts go-live in the middle of the holiday blackout, which the charter forbids. Something must change before work begins, not after the project falls behind.

How Reliable Are the Estimates?

A critical path is only as good as the duration estimates behind it, and these are single-point estimates for work the food bank has never done. Configuration, at 12 weeks, carries the most uncertainty because it depends on how many of the food bank's practices fit the vendor's standard settings. The project team therefore also asked the vendor for optimistic and pessimistic figures: 10 weeks if the standard setup fits well and 16 weeks if significant changes are needed. Using the common three-point weighting of one optimistic, four most likely and one pessimistic estimate divided by six, the expected duration is about 12.3 weeks, slightly longer than the estimate used in Table 1. The pessimistic case would push cutover four weeks later, well into the holiday period. This does not change the recommendation below, but it shows why configuration progress should be the first item in every status meeting and why the contingency reserve should not be spent on anything else until configuration is complete.

Two Ways to Shorten the Schedule

The project needs to recover at least one week, and preferably two to leave a buffer. There are two standard options (Project Management Institute [PMI], 2021).

Crashing adds resources to a critical activity. The vendor offers a second configuration consultant for 24,000 dollars, which would shorten configuration from 12 to 10 weeks. That recovers two weeks, but it draws on 40 percent of the 60,000 dollar contingency reserve before the project has started, and adding a new person to configuration work can slow it at first while they learn the food bank's setup.

Fast-tracking overlaps activities that were planned in sequence. Pantry training could begin two weeks before the pilot ends, using the lessons from the first four weeks of the pilot, rather than waiting for all six weeks. That also recovers two weeks and costs almost nothing, but it adds risk: if the last weeks of the pilot reveal a problem with the ordering portal, the training materials would need to be revised and some pantries retrained.

Recommendation

The project should fast-track pantry training and keep the configuration consultant as a fallback. Overlapping two weeks of pantry training with the end of the pilot moves cutover to week 36, about a week ahead of the deadline, without spending contingency. The risk of rework is manageable because most portal problems appear in the first weeks of a pilot, and the training can be delivered first to the eight pilot pantries, who already know the system. If configuration runs late, the project manager can still crash it with the second consultant, which is why the contingency should remain untouched for now. The float on data cleanup and hardware should be protected rather than consumed early, and the two parallel critical branches, migrations and warehouse testing, should be reviewed weekly because either can push the whole schedule past the holiday.

References

Kelley, J. E., Jr., & Walker, M. R. (1959). Critical-path planning and scheduling. In Papers presented at the December 1-3, 1959, eastern joint IRE-AIEE-ACM computer conference (pp. 160-173). Association for Computing Machinery. https://doi.org/10.1145/1460299.1460318

Kerzner, H. (2022). Project management: A systems approach to planning, scheduling, and controlling (13th ed.). Wiley.

Project Management Institute. (2021). A guide to the project management body of knowledge (PMBOK guide) (7th ed.). Project Management Institute.