sustainability Article Construction Contract Administration Performance Assessment Tool by Using a Fuzzy Structural Equation Model Murat Gunduz 1, * and Hesham Ahmed Elsherbeny 2 1 Department Civil Engineering, Qatar University, Doha P.O. Box 2713, Qatar 2 Engineering Management Program, College of Engineering, Qatar University, Doha P.O. Box 2713, Qatar; he1512830@student.qu.edu.qa * Correspondence: mgunduz@qu.edu.qa Received: 2 December 2019; Accepted: 8 January 2020; Published: 10 January 2020   Abstract: The contract administration process is inevitably complex, and improper performance of the associated tasks and procedures may lead to disputes between the contracting parties whilst further driving against the sustainability bottom lines. Therefore, this paper proposes an assessment tool to improve the implementation of construction contract administration (CCA) through a multi-dimensional construction contract administration performance model (CAPM), construction contract administration performance index (CCAPI), and a mobile software to assess the CCA performance at the project level by integrating the crisp value of the fuzzy set theory within a second-order confirmatory factor analysis of the structural equation modeling technique. A hybrid mobile application (CAPM) is developed using the Ionic framework which can run either in full model mode or short model mode with 93 and 33 key construction administration factors, respectively. Assessment of sustainability practices in the area of contract administration is a part of the holistic model and CAPM defines 13 major key indicators relevant to social and environmental sustainability while economic sustainability is scattered over the rest of the CAPM indicators. The CAPM is practically implemented in 13 international construction projects and the results reveal that the proposed tool is reasonably captured in the different performance levels of CCA, and we conclude a low level of implementing in risk management. As part of the holistic model, assessment of sustainability practices in the area of contract administration is separately discussed and the study reveals the need to improve the environmental and social sustainability practices in contract administration. Keywords: contract administration; fuzzy structural equation model; contract administration performance index; sustainability indicators in contract administration 1. Introduction While the construction industry is as an enabler for achieving nationwide goals in modern society, the construction projects have a substantially high rate of business failure, bankruptcy, delays, losses and budget overruns, deviation from standards, quality issues and waste of resources [1]. Moreover, the construction projects are affected by economic, environmental, and social-political issues that result from the involvement of many stakeholders in the project. Not only this but, the construction industry is facing many challenges including low productivity, poor compliance, lack of adequate collaboration and information sharing, and poor payment practices [2]. Furthermore, the challenges of construction projects may be caused by improper management, lack of technical skills, lack of innovation and technology, financial resources, inadequate coordination, integration, communication, and control Sustainability 2020, 12, 523; doi:10.3390/su12020523 www.mdpi.com/journal/sustainability