As-Built But-For Schedule Delay Analysis Methodology

This document is a technical report detailing the As-Built But-For Schedule Delay Analysis (ABBF), a retrospective method used in construction project management to evaluate delays. The ABBF method determines the earliest possible completion dates for project activities by analyzing owner-caused compensable delays and contractor-caused noncompensable delays. The report outlines the methodology's appropriateness, the construction of the As-Built Calculation Schedule, and the quantification of delays. It explains how the ABBF method differs from other analysis techniques, such as Time Impact Analysis (TIA) and Update Impact Analysis (UIA), emphasizing its focus on actual project timelines rather than planned schedules. The document also addresses the complexities involved in performing the ABBF analysis, including the necessity of converting as-built schedules into a planned format for accurate evaluation. Additionally, it discusses the implications of concurrent delays and the potential compensability of owner-caused delays, providing a comprehensive understanding of the ABBF methodology's application in the construction industry.