Green, lean, Six Sigma barriers at a glance: A case from the construction sector of Pakistan

The construction sector consumes a massive amount of resources, produces a large volume of emissions, and generates large-scale waste. Earlier studies considered green, lean, and Six Sigma (GLS) approaches as being critical in the construction process for the optimum use of resources, cost reduction, quality improvement, and sustainability. Pakistan's construction sector is struggling to implement sustainable and improved construction processes. This work attempts to analyse barriers to the GLS construction process (GLSCP) through a literature review and expert opinion. During brainstorming sessions, a group of experts validated the barriers and developed contextual relationships among them using a questionnaire. An 11-level hierarchal model was developed by implementing interpretive structural modelling (ISM) methodology. The Matriced Impacts Croise's Multiplication Appliqee a UN Classement (MICMAC) technique was applied to delineate these barriers into the categories of 'driving', 'linkage', and 'dependent'. While the findings indicate that all barriers are critical and play a role in hindering the application of GLS in the construction process, the top five critical barriers to GLS are an unstable political environment, lack of government policy, lack of customer involvement and awareness of GLS, lack of funds, and lack of top leadership support for GLS adoption. This work may assist the government, policy-makers, and managers by providing insights into the barriers and in developing strategies for the possible adoption of GLS concepts for sustainable construction and improved quality.