A Fuzzy-AHP and House of Quality integrated approach for Lean Construction Concepts Assessment in Off-site Construction

Abstract

Lean Construction (LC) combines theoretical research and industry best practices in an off-site industrialized construction environment that adopts Lean Manufacturing (LM) concepts and the know-how to reduce waste in the end-to-end lean construction process. Off-site construction industries strive to implement lean manufacturing theory and application to maximize the allocation of their resources, reduce construction waste, and optimize processes to be economically competitive. However, decision-makers usually encounter barriers while selecting the best lean tools for successful integration. Those barriers are organizational priorities, mass customization, process limitation, and improvement consensus. As a result, lean practitioners tend to implement tools such as Value Stream Mapping (VSM), Process Activity Mapping (PAM), Root Cause Diagram (RCD), Failure Mode Effect Analysis (FMEA), Pareto Analysis (PA) to analyze and propose improvements to a manufacturing process effectively. However, the construction industry lacks a tool that can assess the effectiveness of the lean construction concepts implementation. Thus, this paper proposes an innovative approach to select and evaluate the appropriate lean concepts implemented in an off-site industrialized factory. Firstly, the assessment matrix utilizes Fuzzy-AHP in a pairwise comparison to determine the relationships and calculate the correlations between lean concepts based on the designed hierarchy structure. Secondly, the House of Quality (HoQ) matrix will be integrated to prioritize the selection criteria based on the company's strategic requirements and customer requirements. Finally, the proposed multi-criteria multi-decision ranking matrix is able to prioritize the top lean concepts and demonstrate their combinational impact by eliminating participant's subjectivity, bias, and preferences. The proposed assessment matrix was implemented in an off-site panelized construction case study to prove its effectiveness and validity. The results presented the synergies between different lean concepts combinations and their importance in a lean construction environment.