Schedule Compression
Analyse a baseline critical path, evaluate crash limits and crash cost slopes, select the least-cost critical activity, compress the schedule step by step, and compare crashing with fast tracking.
Compress the Schedule Without Losing Control of the Logic.
Schedule compression seeks to reduce project duration without changing project scope. This demonstration starts with a 16-day baseline schedule, identifies the critical path, evaluates crash alternatives using cost slope, then compresses the critical path to a 14-day target and compares the result with a fast-tracking alternative.
- Build and calculate the baseline schedule.
- Identify the current critical path before considering compression.
- Review normal duration, crash duration, normal cost, and crash cost.
- Calculate crash cost slope for every activity.
- Select compression actions only where they can reduce project duration.
- Recalculate the schedule after every compression step.
- Compare cost-driven crashing with risk-driven fast tracking.
Schedule Compression — Step by Step
Complete each locked stage before the next unlocks. Every reveal changes the compression visual so the schedule consequence remains visible beside the decision.
Review the Baseline Activity Data
Network, Critical Path and Compression Economics
Baseline activity data are revealed one activity at a time.
Focus Mode moves you to the Guided Demonstration, then hides the rest of the page while keeping the current learning stage and compression visual together. Zoom affects only the visual pane.
Schedule and Crash Economics
Values appear progressively with the guided sequence. Crash cost slope is shown only after it has been calculated.
| Activity | Predecessor(s) | Normal Duration | Crash Duration | Normal Cost | Crash Cost | Crash Slope / Day | ES | EF | Total Float |
|---|
Build Your Own Compression Plan
Experiment Mode is isolated from the guided example. Crash any activity within its allowable limit, optionally overlap Activity E with Activity D by up to two days, and test whether your plan meets the target duration.
Quick Knowledge Check
Core Rules and Decision Logic
| Concept | Rule / Formula | Interpretation |
|---|---|---|
| Crash Cost Slope | (Crash Cost − Normal Cost) / (Normal Duration − Crash Duration) | Incremental direct cost per unit of duration reduction. |
| Crashing | Add resources/cost to shorten eligible activity duration | Normally focus on current critical-path activities. |
| Fast Tracking | Overlap work that was originally planned sequentially | May reduce duration but increases coordination, rework, and technical risk. |
| Critical-Path Rule | Shortening a noncritical activity does not necessarily shorten the project | Compression must reduce a controlling path. |
| Recalculation Rule | Recalculate after every compression action | The critical path may change after each step. |
| Multiple Critical Paths | All controlling paths may need to be shortened | Crashing only one of several equal critical paths may not reduce project duration. |
Crashing
Primary trade-off: time versus direct cost/resource use.
Use when: critical activities are compressible and additional resources or expenditure are feasible.
Fast Tracking
Primary trade-off: time versus execution risk/rework exposure.
Use when: predecessor-successor work can be safely overlapped without unacceptable technical or coordination risk.