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Gantt Chart with Critical Path Highlighted

Run the Gantt MicroSim Fullscreen

About This MicroSim

This MicroSim shows a small CRM rollout project as a 12-week Gantt chart with twelve tasks across twelve swim lanes. The critical path — the chain of tasks where any delay slips the entire Go-Live — is rendered in mascot-magenta. Tasks with slack (the freedom to slip without slipping the project) are rendered in mascot-emerald, and the slack itself can be revealed as a faint coral trailing region.

How to Use

  1. Drag any task bar to a new start date to see whether the move pushes the project finish
  2. Click Show Slack on Non-Critical Tasks to reveal each task's free time
  3. Click Reset Schedule to undo your changes
  4. Watch the status message: green when the project still finishes on day 84, magenta when it slips

Critical Path

The eight critical-path tasks (in order):

  1. Charter Signed (milestone)
  2. Requirements Gathering (2 weeks)
  3. Vendor Selection (2 weeks)
  4. Configuration (3 weeks)
  5. Data Migration Build (2 weeks)
  6. UAT (2 weeks)
  7. Cutover (1 week)
  8. Go-Live (milestone)

The three off-critical-path tasks — Test Environment Setup, Training Materials, and Training Delivery — each have slack, meaning they can slip a few days without affecting Go-Live.

Embedding This MicroSim

<iframe src="https://dmccreary.github.io/information-systems/sims/gantt-with-critical-path/main.html"
        height="722px" width="100%" scrolling="no"></iframe>

Lesson Plan

Learning Objectives

By the end of this activity, students will be able to:

  1. Read a Gantt chart and identify task durations and dependencies
  2. Distinguish critical-path tasks from non-critical tasks by their effect on project finish
  3. Predict the schedule effect of moving any task by a given number of days
  4. Explain why "slack" matters and where to find resources to compress the critical path

Suggested Activities

  1. Critical Path ID (5 min) — Without dragging, students should identify which 8 of the 12 tasks lie on the critical path
  2. Schedule Slip Drill (10 min) — Drag Configuration to start one week late; record what happens to Go-Live
  3. Compression Challenge (15 min) — Students propose how to compress the schedule by 2 weeks. Where do they add resources, and why?
  4. Slack Reading (10 min) — Toggle slack on. For each non-critical task, write the maximum number of days it could slip without becoming critical

Assessment

  • Identify the critical path in a fresh Gantt chart drawn on the board
  • Given a task's slack value, predict whether moving it by N days affects the project finish
  • Explain why compressing a non-critical task does not shorten the project

References

  • PMI (2021). PMBOK Guide, 7th ed., Schedule Management.
  • Kelley, J. & Walker, M. (1959). Critical-Path Planning and Scheduling.