Comprehensive maintainability scoring system (COMASS) for commercial buidings in tropical climate of Singapore

Dearth of holistic grading system to integrate design-construction-maintenance guidelines and their maintainability impacts causes prevalent and recurrent defects. Proposed COMASS is a decision-enhancement tool applicable for part or whole of a new or existing building to select the best strategy. Data was collected through casestudys, surveys and face-to-face interviews of facility managers. 'Defect Library' is analysis of causes and criticality of 319 types of observed defects for nine major building elements using FMECA. A total of 731 defect-mitigating checklist factors along with scoring logic constituted 'Maintainability Handbook'. Using objective and subjective parameters, AHP integrated building elements using 12 sets of relative weights for various location-height combinations. Values were coherent with expertsb subjective opinions. Predictive accuracy of COMASS was found satisfactory through operational validity and sensitivity testing via Monte-Carlo simulation for a hypothetical multi-tenant office tower at CBD. A user-friendly online application was also developed. The generic method can be applied for other building types or climates and aspires to improve the maintainability profile of buildings significantly.