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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


Purposeโ€‹

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


Why This Mattersโ€‹

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 Overviewโ€‹

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 Analysisโ€‹

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-Builtโ€‹

Overview:โ€‹

Compare original schedule to actual completion dates.

Process:โ€‹

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

Limitations:โ€‹

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

When to Use:โ€‹

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

Method 2: Impacted As-Plannedโ€‹

Overview:โ€‹

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

Process:โ€‹

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

Strengths:โ€‹

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

Limitations:โ€‹

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

When to Use:โ€‹

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

Method 3: Collapsed As-Built (But-For)โ€‹

Overview:โ€‹

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

Process:โ€‹

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

Strengths:โ€‹

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

Limitations:โ€‹

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

When to Use:โ€‹

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

Method 4: Time Impact Analysis (TIA)โ€‹

Overview:โ€‹

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

Process:โ€‹

  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:โ€‹

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

Requirements:โ€‹

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

When to Use:โ€‹

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

Method 5: Windows Analysisโ€‹

Overview:โ€‹

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

Process:โ€‹

  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:โ€‹

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

Limitations:โ€‹

  • Very labor intensive
  • Requires excellent records
  • Complex presentation

When to Use:โ€‹

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

Critical Path Analysisโ€‹

Identifying Critical Path:โ€‹

Total Float = 0 โ†’ Activity is critical Total Float > 0 โ†’ Activity has flexibility

Critical Path Shifts:โ€‹

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

Documentation Required:โ€‹

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

Concurrent Delayโ€‹

Definition:โ€‹

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

Types:โ€‹

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

Handling Concurrent Delay:โ€‹

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 Checklistโ€‹

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

Project: ___________________________________________________

Claim Period: ______________________________________________

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

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

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

CONTEMPORANEOUS RECORDS:
โ˜ Daily reports
โ˜ Meeting minutes
โ˜ Progress photos
โ˜ Manpower logs
โ˜ Equipment logs

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

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

Delay Analysis Report Outlineโ€‹

1. Executive Summaryโ€‹

  • Total delay claimed
  • Responsible party allocation
  • Methodology used

2. Project Backgroundโ€‹

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

3. Methodologyโ€‹

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

4. Chronology of Eventsโ€‹

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

5. Delay Analysisโ€‹

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

6. Conclusionโ€‹

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

7. Exhibitsโ€‹

  • Schedules
  • Correspondence
  • Calculations
  • Supporting documents

Common Delay Analysis Errorsโ€‹

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 Requirementsโ€‹

For Complex Claims, Consider:โ€‹

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

Referencesโ€‹

  • 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.

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