Delays are an inherent challenge in construction projects, arising from factors suchas design changes, resource shortages, and unforeseen events. To effectively address these delays, two primary methods of delay analysis are utilized: prospective analysis and retrospective analysis. These approaches differ in timing, purpose, data requirements, and outcomes. This article explores their advantages, disadvantages, and relevance in construction project management, supported by insights from the SCL Protocol and AACE Recommended Practices.
    Prospective analysis is particularly useful during ongoing projects, especially for addressing straightforward delays or meeting contractually required forecasts.

    Methods of Prospective Analysis

    Impacted As-Planned (IAP): Adds delay events to the baseline schedule to evaluate their potential impact. Best for simpler, early-stage delays.

    Time Impact Analysis (TIA): Incorporates delay event subnetworks into the baseline program and recalculates impacts. Ideal for evolving, long-duration projects.

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    What is delay analysis, and why is it important in construction projects?

    Delay analysis identifies and assesses the causes and impacts of delays on a project’s schedule. It is essential for managing time, preventing cost overruns, resolving disputes, and maintaining project accountability.

    What is prospective delay analysis?

    Prospective delay analysis is a forward-looking approach used during an ongoing project. It predicts the potential impacts of delays to help proactively manage and mitigate them.

    Common Methods:

    • Impacted As-Planned (IAP)
    • Time Impact Analysis (TIA)
    When should I use prospective analysis?

    Use it when a project is ongoing, especially for:

    • Forecasting schedule impacts
    • Making real-time adjustments
    • Meeting contractual reporting requirements
    What is retrospective delay analysis?

    Retrospective delay analysis is a backward-looking approach used after a delay or at project completion. It investigates actual events to determine their causes and consequences.

    Common Methods:

    • As-Planned vs. As-Built
    • Time Slice Window Analysis
    • Collapsed As-Built
    Can both methods be used in one project?

    Yes. Projects may begin with prospective analysis and later switch to retrospective for final delay evaluation. However, consistency in data and methodology is crucial during this transition.