Identification of factors and decision analysis of the level of modularization in building construction

In the majority of ordinary housing development projects, instead of using complex multicriteria decision-making systems, companies still rely on expert knowledge, checklists, or similar tools to decide on an appropriate level of modularization. Generally, in these types of projects the level of modularization is mainly driven by site constraints, such as accessibility and harsh weather conditions. Because of the lack of appropriate decision support tools, it is very hard for decision makers to include factors, such as lifecycle costs, quality, productivity, efficiency, and design complexity, into their decision, even if they are willing to do so. Simple decision support tools are required to provide practical assistance to the decision makers to adopt an appropriate level of modularization for such projects. This study, as a part of a broad ongoing research project on the optimum level of modularization in building construction, has compiled the expert knowledge for decision support that enables the decision makers to perform an easy initial feasibility study on the use of an appropriate level of modularization in their construction projects. First, a list of critical decision-making criteria is created. These criteria are obtained from an extensive literature review, qualitative survey questionnaires, and semistructured interviews with researchers and professionals in the construction industry as well as modular manufacturers. Then, using the results, a simple multicriteria decision analysis (MCDA) approach is developed as a practical decision support system to facilitate the decision-making process for selecting appropriate construction systems as well as determining the proper level of modularization for building construction projects. The validation of the study is demonstrated through a local actual case study.