Understanding Collapsed As-Built Analysis
Collapsed as-built analysis is a retrospective delay analysis methodology that starts from actual project completion and systematically removes delay events to determine what completion date would have occurred without those events. This "collapsing" process reveals individual and cumulative delay impacts. Effective construction scheduling software supports collapsed as-built analysis through comprehensive as-built schedule development and analytical capabilities.
Unlike prospective methods that analyze delays as they occur, collapsed as-built works backward from known results. This approach enables analysis even when contemporaneous schedule updates weren't maintained, making it valuable for projects with limited schedule documentation. Your construction management software supports as-built development that enables collapsed analysis.
When to Use Collapsed As-Built
Collapsed as-built analysis suits specific situations where its characteristics provide advantages. Your construction project management software should support this method when circumstances warrant.
Projects with limited contemporaneous schedule updates benefit from collapsed as-built because the method doesn't require historical schedule versions. Starting from as-built status and working backward accommodates documentation limitations.
Final determination of delay impacts uses collapsed as-built because actual results are known. Prospective analyses predicted impacts; collapsed as-built determines what actually happened.
Analysis long after project completion may require collapsed as-built when memories have faded and only the as-built record remains reliable. Your contractor scheduling software preserves the as-built data needed for later analysis.
Developing the As-Built Schedule
Collapsed as-built analysis requires a comprehensive as-built schedule showing actual dates for all project activities. Your best construction scheduling software should support detailed as-built development.
Capture actual start and finish dates for every activity. These dates come from daily reports, pay applications, inspection records, photos, and other contemporaneous documentation. Your construction scheduling software facilitates as-built development.
Include actual logic relationships. How did activities actually connect? Did the planned sequence hold, or did actual work proceed differently? Your construction management software captures actual logic.
Document interrupted activities accurately. If work stopped and restarted, the as-built should reflect actual work patterns rather than simplified continuous durations.
Identifying Delay Events
Before collapsing can begin, identify the delay events to be analyzed. What events allegedly caused delays? Which party is responsible for each event? Your construction project management software organizes event identification.
Categorize events by responsible party. Owner-caused delays, contractor-caused delays, third-party delays, weather, and unforeseen conditions each require separate tracking. Your contractor scheduling software supports event categorization.
Document each event's characteristics. What activities were affected? What was the duration of impact? What evidence supports the event identification? Your best construction scheduling software captures event documentation.
The Collapsing Process
Collapsing removes delay events from the as-built schedule one at a time, recalculating the schedule after each removal to determine that event's impact. Your construction scheduling software supports this iterative process.
Start with the complete as-built schedule reflecting actual project completion. This schedule includes all activities with actual dates and actual logic relationships.
Remove one delay event by eliminating or reducing activities associated with that event. Recalculate the schedule to determine revised completion. Your construction management software performs these calculations.
The difference between completion before and after removing the event represents that event's delay impact. Record this impact before proceeding to the next event.
Continue removing events until all analyzed events are extracted. The final collapsed schedule shows what completion would have been without any analyzed delays.
Order of Extraction
The order in which events are extracted can affect results, particularly when events interact or occur concurrently. Your construction project management software should support different extraction sequences.
Chronological extraction removes events in the order they occurred. This approach mirrors how delays actually accumulated during construction. Your contractor scheduling software supports chronological analysis.
Reverse chronological extraction removes latest events first. This approach may reveal different impact allocation when early events consumed float that later events would have used.
Responsibility-based extraction removes all events of one type (owner delays, contractor delays) before others. This grouping may support or undermine claims depending on how delays interact.
Handling Concurrent Delays
Concurrent delays—where multiple causes affect the same period—require special attention in collapsed as-built analysis. Your best construction scheduling software supports concurrent delay evaluation.
When extracting concurrent delays, results depend on extraction order. If owner and contractor delays both affected the critical path simultaneously, extracting owner delays first may show contractor delays as non-critical, and vice versa.
Document concurrent situations clearly. Regardless of extraction sequence, the factual concurrency should be evident in analysis documentation. Your construction scheduling software captures concurrent delay information.
Consider analyzing concurrent periods with both extraction sequences to understand how order affects results. This sensitivity analysis supports more complete understanding.
Advantages of Collapsed As-Built
Collapsed as-built analysis provides several advantages that make it valuable in appropriate situations. Your construction management software supports leveraging these advantages.
The method works with limited schedule documentation. If contemporaneous updates weren't maintained, collapsed as-built can still provide meaningful analysis using as-built data. Your construction project management software enables as-built development from various sources.
Results reflect actual project completion rather than predictions. Collapsed as-built shows what actually happened, not what might have happened. This factual grounding supports analysis credibility.
The systematic extraction process is transparent and reproducible. Others can follow the same process and verify results.
Limitations and Criticisms
Collapsed as-built analysis has recognized limitations that should be acknowledged. Your contractor scheduling software supports analysis while recognizing these limitations.
Hindsight bias affects analysis. Knowing actual results may influence how analysts construct the as-built or evaluate delay impacts. Strive for objectivity despite knowing outcomes.
As-built development involves judgment. Determining actual logic relationships from imperfect documentation requires interpretation that different analysts might perform differently.
Extraction order sensitivity can produce different results depending on analytical choices. Document methodology clearly to enable meaningful evaluation of results.
Documentation Requirements
Thorough documentation supports credible collapsed as-built analysis. Your best construction scheduling software captures comprehensive analysis documentation.
Document as-built development methodology. What sources were used? How were dates determined? What judgments were made about logic relationships?
Document delay event identification. What events were analyzed? What evidence supports each event? How was duration determined?
Document extraction methodology. In what order were events extracted? How were concurrent delays handled? What calculations were performed?
Document results clearly. What impact was determined for each event? What was cumulative impact by responsible party? What confidence level attaches to conclusions?
Comparison with Other Methods
Collapsed as-built represents one of several delay analysis methodologies. Your construction scheduling software should support multiple methods for comparison.
Time impact analysis (TIA) evaluates delays contemporaneously using schedule versions from when delays occurred. TIA is considered more accurate when contemporaneous schedules exist.
Window analysis divides the project into periods and analyzes delays within each window. This approach provides different insights than collapsed as-built.
As-planned vs. as-built comparison shows overall variance but may not establish causation. Collapsed as-built provides more detailed cause-and-effect analysis.
Best Practices for Collapsed As-Built
Develop comprehensive as-built schedules from multiple data sources. More complete as-built data produces more credible analysis. Your construction management software supports thorough as-built development.
Document methodology clearly. Analysis choices affect results; clear documentation enables evaluation. Your construction project management software captures methodology documentation.
Acknowledge limitations appropriately. Where data is limited or judgments significant, note the uncertainty. Overstated confidence undermines credibility.
Consider sensitivity analyses. Where choices affect results, testing alternatives provides more complete understanding of delay impacts.
Collapsed as-built analysis provides a systematic method for determining delay impacts when contemporaneous schedule analysis wasn't performed. When implemented carefully using comprehensive contractor scheduling software and as-built data, collapsed as-built enables meaningful retrospective analysis of construction schedule delays.