Generic Method of Grading Building Defects Using FMECA to Improve Maintainability Decisions

Abstract

To improve building maintainability by preventing defects, a scientific maintainability scoring system necessitates a centralized database of defects and their systematic analysis or grading. Unlike causes, impacts of defects are not well defined. This research establishes bottom-up, qualitative failure mode effect and criticality analysis (FMECA) as a suitable defect grading tool and develops criticality parameters applicable for buildings. For two major systems, nine subsystems, and 62 components of Singapore commercial buildings, 319 defects were identified. Thirty-four experienced facility managers graded 45% of them as critical in a five-point Likert scale during a face-to-face questionnaire. Most critical defects were from five mechanical-electrical subsystems, namely, sanitary plumbing, HVAC, elevator, electrical, and fire protection. They are rare but significantly affect users and system performance. Though four civil-architectural subsystems were simpler, their defects showed higher frequency and economic impact. These subsystems were basement, facade, wet area, and roof. Here, structural members are excluded as beyond the scope of regular maintenance. The proposed method aptly evaluated defects from both complex and simple subsystems whose general characteristics matched with the identified nature of associated defects. The knowledge elicited will contribute to developing a Comprehensive Maintainability Scoring System (COMASS) with guidelines weighted as per their ability to mitigate both critical and noncritical defects.