A function-based lean construction methods ontology supporting the lean implementation planning process developed for construction projects

Lean Construction, also known as Lean Project Delivery, is defined as respect and relationship-oriented holistic project design and delivery process. Its overarching aim is to maximize value for all stakeholders, simultaneously emphasizing and materializing the customer’s voice through systematic, synergistic, and continuous improvement in all project aspects such as contractual arrangements, design development, construction process design, means and methods selection, supply chain, workflow reliability on the job-site, post-construction operations, and maintenance. Although the Lean philosophy originated in the manufacturing domain, since the 1900s, it has been profusely adopted within the architecture engineering and construction (AEC) industry via Lean Construction methods designed to fit the project-based nature. Such methods have been known and documented to benefit a project, including customer- satisfaction, job-site safety, risk management, sustainability, profitability, quality, and worker productivity. Together with their interrelated components, they encompass the Lean Construction domain. Throughout this time, since its first inception, Lean Construction practitioners have identified numerous barriers that need resolving for successful and sustainable Lean adoption and implementation on their projects. Research focusing on project-level Lean implementations indicated that the key barriers are the project team’s lack of awareness, education, and understanding related to Lean Construction principles and methods. This limitation presents inconsistent and inefficient approaches in planning project-specific Lean implementations. Hence, any form of industry-wide benchmarking becomes difficult for comparing project performance related to Lean implementation. A root-cause analysis using evidence from literature followed by a set of exploratory interviews with Lean Construction experts was performed to understand this issue more deeply. Combined results from literature review and expert interviews revealed that there is a significant opportunity to improve the project team’s knowledge and ability to systematically plan for Lean implementation by providing a structured planning approach and a standard vocabulary related to Lean Construction methods. This study was completed in three stages: process development, process validation, and ontology development and evaluation. In the first stage, a focused literature review of Lean implementation studies was conducted alongside semi-structured interviews with expert Lean practitioners. This combined approach helped determine the key steps and strategies to guide project teams to systematically plan Lean implementation on a project. In addition, such steps and strategies were used to map the baseline Lean implementation planning process. In the second stage, the baseline process was validated using a single in-depth case study, clarifying the associated requirements such as timeline and duration of collaborative sessions, resource commitments, and educational and training needs. In the third stage, information about Lean Construction methods was systematically gathered, organized, and analyzed using an ontological approach. From this approach, several entities were identified as essential categories belonging to the overarching Lean Construction domain. Furthermore, it was derived from expert opinion that although all such categories contribute to Lean implementation, its crux lies in the project team’s ability to select appropriate Lean methods specific to their project. Therefore, a function-based Lean Construction methods ontology was created by honing the Lean methods and associated project functions and using a four-step iterative process comprising requirements specification, knowledge acquisition, conceptualization, and documentation. Finally