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Schedule Delay Analysis Methods

Document Type: Advanced Procedure
Version: 1.0
Last Updated: February 2026
Distribute To: Project Managers, Schedulers, Claims Personnel
Complexity: Enterprise-level


Purpose

Provide sophisticated schedule delay analysis methodologies aligned with AACE International recommended practices for use in claims, disputes, and project controls.


Why This Matters

For enterprise contractors:

  • Delay claims can be worth millions
  • Proper methodology determines success
  • Courts and arbitrators expect sophistication
  • Owners increasingly have sophisticated schedulers
  • Insufficient analysis = denied claims

Delay Analysis Methods Overview

MethodComplexityProspective/ RetrospectiveBest Used For
As-Planned vs. As-BuiltLowRetrospectiveSimple delays, low value
Impacted As-PlannedMediumProspectiveDuring project, time extensions
Collapsed As-Built (But-For)HighRetrospectiveClaims, litigation
Time Impact Analysis (TIA)HighBothGold standard for claims
Windows AnalysisHighRetrospectiveComplex, multiple delays

RP 29R-03: Forensic Schedule Analysis

Key Principles:

  1. Use contemporaneous schedules
  2. Document delay events
  3. Apply appropriate methodology
  4. Quantify critical path impact
  5. Address concurrent delays
  6. Validate with actual performance

Method 1: As-Planned vs. As-Built

Overview:

Compare original schedule to actual completion dates.

Process:

  1. Identify planned start/finish dates
  2. Document actual start/finish dates
  3. Calculate variance
  4. Identify causes

Limitations:

  • Doesn't prove causation
  • Doesn't address concurrent delays
  • May not reflect schedule updates
  • Generally insufficient for litigation

When to Use:

  • Low-value claims
  • Simple, single-cause delays
  • Initial screening

Method 2: Impacted As-Planned

Overview:

Add delay events to as-planned schedule to show impact.

Process:

  1. Start with baseline schedule
  2. Insert delay activities
  3. Re-calculate critical path
  4. Measure project delay

Strengths:

  • Shows theoretical impact
  • Useful for time extension requests
  • Relatively straightforward

Limitations:

  • Doesn't reflect actual performance
  • Baseline may not have been realistic
  • Assumes logic intact

When to Use:

  • Prospective analysis during project
  • Time extension requests
  • What-if scenarios

Method 3: Collapsed As-Built (But-For)

Overview:

Remove delay events from as-built schedule to show "but-for" completion.

Process:

  1. Create as-built schedule
  2. Remove owner/excusable delay activities
  3. Re-calculate to show "but-for" completion
  4. Difference = compensable delay

Strengths:

  • Based on actual performance
  • Shows what would have happened
  • Accepted by many tribunals

Limitations:

  • Requires accurate as-built
  • Subtractive approach challenged
  • Concurrent delay issues

When to Use:

  • Retrospective claims
  • After project completion
  • When as-built is well-documented

Method 4: Time Impact Analysis (TIA)

Overview:

Insert delay events into schedule at time of occurrence, measure impact contemporaneously.

Process:

  1. Identify delay event
  2. Use schedule update just before event
  3. Insert delay activity with logic ties
  4. Calculate impact to completion
  5. Repeat for each event

The Gold Standard:

  • AACE preferred method
  • Most defensible
  • Addresses concurrent delays
  • Matches contemporaneous records

Requirements:

  • Regular schedule updates
  • Documented delay events
  • Logic ties understood
  • Skilled scheduler

When to Use:

  • Complex delays
  • High-value claims
  • Litigation/arbitration
  • Multiple delay causes

Method 5: Windows Analysis

Overview:

Divide project into time "windows" and analyze each period.

Process:

  1. Divide project into periods (monthly, milestone-based)
  2. For each window:
    • Identify critical path
    • Measure delay
    • Attribute to responsible party
  3. Sum delays across windows
  4. Net excusable vs. non-excusable

Strengths:

  • Handles concurrent delays well
  • Shows delay development over time
  • Matches monthly reporting

Limitations:

  • Very labor intensive
  • Requires excellent records
  • Complex presentation

When to Use:

  • Complex projects with many delays
  • Concurrent delay situations
  • Large claims requiring detailed analysis

Critical Path Analysis

Identifying Critical Path:

Total Float = 0 → Activity is critical Total Float > 0 → Activity has flexibility

Critical Path Shifts:

  • Delays to critical activities extend project
  • Non-critical delays may become critical
  • As-built critical path may differ from planned

Documentation Required:

  • Baseline schedule with critical path
  • Updates showing critical path changes
  • Float consumption tracking
  • Near-critical path monitoring

Concurrent Delay

Definition:

Two or more delays occurring at the same time, both impacting completion.

Types:

TypeOwner DelayContractor DelayResult
True concurrentCriticalCriticalTime only, no costs
SequentialFirstSecondApportion
DominantMinorMajorContractor bears

Handling Concurrent Delay:

Approaches vary by jurisdiction:

  • Apportionment (some courts)
  • Malmaison approach (UK - time but no costs)
  • First-in-line (whoever caused first delay)
  • Contractor bears all (strict approach)

Best Practice:

  • Document meticulously
  • Separate analysis for each delay
  • Identify dominant cause where possible
  • Prepare for apportionment

Schedule Analysis Checklist

================================================================
DELAY ANALYSIS PREPARATION CHECKLIST
================================================================

Project: ___________________________________________________

Claim Period: ______________________________________________

================================================================

SCHEDULE DOCUMENTATION:
☐ Baseline schedule (accepted)
☐ All schedule updates (monthly)
☐ As-built schedule
☐ Schedule narratives
☐ Recovery schedules (if any)
☐ Acceleration plans (if any)

DELAY DOCUMENTATION:
☐ Delay events log (with dates)
☐ Notice letters sent
☐ RFIs related to delays
☐ Weather records
☐ Force majeure documentation
☐ Owner/architect correspondence

CONTEMPORANEOUS RECORDS:
☐ Daily reports
☐ Meeting minutes
☐ Progress photos
☐ Manpower logs
☐ Equipment logs

ANALYSIS ELEMENTS:
☐ Critical path identified (each period)
☐ Float consumption tracked
☐ Concurrent delays addressed
☐ Methodology documented
☐ Cause-and-effect established

================================================================

Delay Analysis Report Outline

1. Executive Summary

  • Total delay claimed
  • Responsible party allocation
  • Methodology used

2. Project Background

  • Contract scope and schedule
  • Key milestones
  • Baseline schedule overview

3. Methodology

  • Analysis method selected
  • Why appropriate
  • Data sources
  • Assumptions

4. Chronology of Events

  • Timeline of delay events
  • Impact of each event
  • Critical path analysis

5. Delay Analysis

  • Detailed calculations
  • Schedule excerpts
  • Float analysis
  • Concurrent delay treatment

6. Conclusion

  • Days of delay by cause
  • Compensable vs. excusable
  • Summary schedule impact

7. Exhibits

  • Schedules
  • Correspondence
  • Calculations
  • Supporting documents

Common Delay Analysis Errors

ErrorProblemPrevention
No critical path analysisCan't prove project delayAlways analyze CP
Ignoring floatOver-claimsTrack float consumption
Using wrong baselineFoundational errorVerify accepted schedule
Ignoring concurrent delaysClaim rejectedAddress head-on
After-the-fact schedulesNot contemporaneousUse real updates
Missing documentationCan't support claimDocument in real-time

Expert Requirements

For Complex Claims, Consider:

Scheduling Expert:

  • CPM scheduling experience
  • Construction background
  • Forensic analysis experience
  • Credibility with tribunals

Expert Report Should Include:

  • Qualifications
  • Materials reviewed
  • Methodology
  • Opinions and basis
  • Supporting exhibits

  • Schedule Management Procedure
  • Claims Procedures
  • Change Order Management
  • Daily Reporting

References

  • AACE International RP 29R-03 (Forensic Schedule Analysis)
  • AACE International RP 52R-06 (Time Impact Analysis)
  • SCL Delay and Disruption Protocol (UK)
  • Long International papers on delay analysis

Template provided by support.construction. Enterprise-level schedule analysis for sophisticated claims.