Citation: Pedrosa, M.; Arantes, A.; Cruz, C.O. Barriers to Adopting Lean Methodology in the Portuguese Construction Industry. Buildings 2023, 13, 2047. https://doi.org/10.3390/ buildings13082047 Academic Editor: Osama Abudayyeh Received: 30 June 2023 Revised: 7 August 2023 Accepted: 8 August 2023 Published: 10 August 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). buildings Article Barriers to Adopting Lean Methodology in the Portuguese Construction Industry Manuel Pedrosa 1 , Amílcar Arantes 2 and Carlos Oliveira Cruz 2, * 1 Instituto Superior Técnico, Universidade de Lisboa, 1649-004 Lisboa, Portugal; manuelpmpedrosa@tecnico.ulisboa.pt 2 CERIS, Instituto Superior Técnico, Universidade de Lisboa, 1649-004 Lisboa, Portugal; amilcar.arantes@tecnico.ulisboa.pt * Correspondence: oliveira.cruz@tecnico.ulisboa.pt Abstract: The Lean methodology allows for the streamlining of management and production systems to reduce costs. In the case of the construction sector, the goal is to optimize processes, reduce waste, increase product quality, and increase client satisfaction. These have been areas where construction, as a sector, is struggling to deliver substantial results. Despite the potential benefits associated with Lean approaches, there has been significant resistance from the construction industry. The main objective of this research is to identify the barriers to applying Lean methodology in the Portuguese construction sector. This will contribute to understanding why Lean is not gaining traction among construction stakeholders and help to identify improvement areas replicable in similar markets. Initially, the barriers were identified based on a comprehensive literature review, and those barriers were evaluated based on their importance using a survey responded to by construction sector professionals. Based on the survey’s results, 15 barriers were considered critical. Additionally, a combined ISM model and MICMAC analysis was developed to study the relations between these barriers and the driving and dependence power of each one of the critical barriers. The results obtained show that the main barriers are the lack of support and commitment from top management, a lack of organizational communication, a lack of communication and transparency between stakeholders, unsuitable organizational structures, a lack of adequate Lean awareness and understanding, management resistance to change, and employees’ aversion to change and fear of new procedures. Keywords: ISM; Lean methodology; MICMAC; mitigation measures 1. Introduction Construction represents 9% of the EU’s GDP and 13% worldwide. The industry employs 7% of the global workforce [1,2]. In Portugal, the construction sector was 9.9% of the workforce and 5.9% of the country’s GDP in 2008, but due to the economic crisis, its workforce share decreased to 6% in 2013, and its contribution to GDP fell to 3.5% in 2016. As of 2018, it employed 6.1% of the workforce and contributed 3.6% to the country’s GDP. In 2021, the construction sector comprised 5% of Portugal’s total GVA [3,4]. Although the economic relevance of the construction sector is well known, there have been several dimensions where the sector has not delivered substantial improvements, unlike other economic sectors. These dimensions include the overall cost of projects, the level of productivity, the level of innovation, the duration of project completion, compliance with established deadlines, the number of defects and unconformities, the extent of rework required, the degree of customer satisfaction, and the troubling record of health and safety within the industry [5]. Most of these challenges are related to well-known problems in the construction sector, particularly the low level of industrialization and a suboptimal project organization and management model. Buildings 2023, 13, 2047. https://doi.org/10.3390/buildings13082047 https://www.mdpi.com/journal/buildings