On this page I review different Well-known methodologies for Delay Analysis
1-Impact As-Planned: In this method, the analyst lists the excusable delays (or delays where a time extension is owed to the contractor) and inserts the extended duration to the relevant activities. The analyst reads the revised completion date, calculates the days between this date and the as-planned completion date, and determines that these are the number of days owed to the contractor.
2-Collapsed As-Built or “But For”: In this method, the analyst takes the actual as-built schedule and takes out the duration of all the excusable delays (delays rightfully owed to the contractor). This revision forms the collapsed as-built schedule. The analyst reads the completion date on the collapsed as-built schedule and considers this date to be the completion date of the project had the contractor not been delayed. The analyst calculates the days between the collapsed as-built and the completion date from the as-built schedule and considers these days to be the days owed to the contractor.
3-Time Impact Analysis: This method is considered as a ” Cause & Effect ” analysis in that it simulates the impact of the delay event(s) (the “Cause”) on the planned sequence of the remainder activities of an updated program of works at a point just before the occurrence of the delay event(s) (the “Updated” program). The method analyses the modelled impact on the Updated program ( the “Effect”).
4- As Planned vs As-Built: This is a simple technique used to compare the baseline or as-planned schedule to the as-built schedule or a schedule update reflecting progress. This method compares planned start and finish dates with the actual start and finish dates of activities on the as-planned critical and near-critical paths. This identifies delayed starts, extended durations, and late finishes. This method is most effective on simple projects with short durations and one clear critical path that remains consistent throughout the entire project.