Composition and Impact of Reasons for Noncompletion in Construction Projects

Abstract

The Last Planner® System (LPS) uses short systematic cycles of work preparation, shortterm execution commitments and identification of Reasons for Noncompletion (RNCs). LPS based software capture quantifiable information that allows to assess RNC impact on execution. RNCs can be categorized using detailed information and their impact can be obtained assessing task progress and compliance. This research aims to determine the main categories, sources and responsible parties affecting compliance, based on empirical data from 25 High-rise Building (HR) and 25 Industrial Construction (IC) projects. Weekly project information representing 22.636 RNCs was assessed to categorize each RNC by type, source and party. The task, commitment and progress information were used to determine their frequency and impact, based on the duration of the affected task and differences between committed and actual progress. The RNC categories were compared across the sample and between HR and IC projects using statistical analyses. Results showed that approximately two in every three RNCs correspond to factors controllable by the main contractor, while collaboration with the client and subcontractors could allow preventing up to 90% of noncompliance issues.