Advanced Scheduling Techniques

Critical Path Method (CPM): The Step-by-Step Guide

Master the essential project management technique to identify the longest sequence of dependent tasks and determine the shortest possible time to complete your project.

How to Calculate the Critical Path

Step 1: The Forward Pass (Early Dates)

Determines the Earliest Start (ES) and Earliest Finish (EF) for each task.

🔹 Formula: EF = ES + Duration
🔹 Start with the first task at ES = 0.
🔹 If a task has multiple predecessors, use the highest EF of the previous tasks.

Step 2: The Backward Pass (Late Dates)

Determines the Latest Finish (LF) and Latest Start (LS) without delaying the project.

🔹 Formula: LS = LF - Duration
🔹 Start from the last task and work backwards.
🔹 If a task has multiple successors, use the lowest LS.

Step 3: Calculate Total Float (Slack)

Formula: Float = LS - ES (or LF - EF)

Tasks with zero float are on the Critical Path. Any delay in these tasks will delay the entire project.

Don't do the math manually!

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