window analysis

WINDOW ANALYSIS PROCEDURE IN PRIMAVERA P6

(Also known as “Contemporaneous Schedule Window Analysis” or “As-planned vs As-built Window Analysis”)

Window Analysis evaluates project delays by breaking the schedule into multiple time-windows and comparing progress period by period.

1️⃣ PREPARATION

1. Collect the required data

• Baseline schedule (Approved baseline in P6)
• Progress updates (monthly/weekly updates)
• As-built information
• Delay events list + dates/impacts
• Any approved change orders

2. Set your baseline

1. Go to Project → Assign Baselines
2. Select:

2️⃣ DEFINE THE WINDOWS

A window is typically a period between two updates (e.g., Monthly windows).

Examples:

• Window 1 → Start to Update #1
• Window 2 → Update #1 to Update #2
• … and so on until final update.

3️⃣ DUPLICATE THE SCHEDULE FOR ANALYSIS

For each window, you need a working copy.

1. Go to Projects → Copy
2. Paste as “Window 1 – Analysis”, “Window 2 – Analysis”, etc.
3. Keep the original updates untouched for audit purposes.

4️⃣ PERFORM WINDOW 1 ANALYSIS

Step A: Open “Window 1” project

• Load the as-planned schedule and the first as-built update.

Step B: Set the Data Date

1. Go to Project → Dates
2. Set Data Date = End of Window 1 (e.g., update date)

Step C: Apply actuals

Import or apply:

• Actual start / finish
• Remaining duration
• % complete
• Progress achieved up to Window 1

Step D: Run the Schedule

1. Press F9 (Schedule)
2. Ensure options:

Step E: Compare Baseline vs Updated Schedule

Go to Tools → Tracking → Gantt Chart and compare:

• Total float changes
• Critical path shifts
• Activity delays
• Variances (Start/Finish/Duration)

Step F: Identify delays in Window 1

Classify each delay:

• Excusable vs Non-excusable
• Compensable vs Non-compensable
• Contractor vs Owner
• Critical-path impacts

Document:

• Delay cause
• Impact days
• Activities affected
• Whether acceleration/mitigation happened

5️⃣ PERFORM WINDOW 2, 3, 4… ANALYSIS

Repeat the same process for each new schedule window:

For each Window:

1. Copy the updated schedule
2. Set Data Date to next update
3. Apply actuals
4. Schedule the project
5. Review float & critical path changes
6. Identify delays unique to each window
7. Record cumulative impacts

6️⃣ BUILD THE WINDOW ANALYSIS REPORT

For each window, include:

A. Period description

• Dates from → to
• Activities worked
• Major progress events

B. Baseline vs Period Variance

• Start variances
• Finish variances
• Float consumption
• Critical-path movement

C. Delay Events

For each delay:

• Start date of delay
• Activities affected
• Critical path effect
• Number of delay days
• Responsible party

D. Cumulative delay impact

At the final window, you identify:

• Total project delay
• Attribution of delay by window
• Contractor/Owner delays
• Extension-of-Time entitlement

7️⃣ FINAL OUTPUT

You should now have: ✔ A window-by-window delay breakdown ✔ A timeline of critical path shifts ✔ Delay attribution (Contractor vs Owner) ✔ Support for Extension-of-Time claims