Validation of a Multi-Criteria Decision Support System for Low-Cost Green Building Materials and Components

Abstract

In an industry where objectivity is sought, validation ascertains the reliability of a system and investigates the credibility of the theoretical basis upon which it is built. The performance of a decision-support system is most often determined by the external validation data rather than the development data. This paper illustrates the validation of a multicriteria decision-support system designed to aid more informed and sustainable material choices at the earliest stages of the design. The main objectives of this exercise are to establish the computational correctness of the software, and evaluate the reliability of the decisions made by the system when formulating decisions regarding the selection of low-cost green building materials and components at the conceptual and crucial stages of the design process. Data collected from samples of ten (10) randomly selected research experts and practicing professionals —who influence material choice decisions and represent various fields in the Nigerian housing construction industry, were used to demonstrate the decision-making capabilities, limitations and appropriateness of the model. In view of the complex nature of this research, an on-going case study project was used to further showcase how well the MSDSS model could be applied to real-life material-selection problems, by comparing the outputs from the model to monitored data from the proposed building project. The key contribution to the assessment of designers’ choice of materials during design engagement is the novel inclusion of the social-cultural and sensorial variables as key indicators of the material selection decision-making process. This study concludes that the ability of the model to discern and prioritise material choices, in terms of their environmental, technical, sociocultural, sensorial and economic impacts— evidenced by an orderly ranked scale of material utility indices, portends a reasonable indication of its reliability, validity and practical usability for further studies.