Using 4D models for tracking project progress and visualizing the owner's constraints in fast-track retail renovation projects

One of the challenges of managing fast-track projects is the high level of uncertainty in both project definition and scheduling. Thus, communicating this project information among stakeholders becomes crucial for its success. One of the key stakeholders is the owner, who needs this information to guide its decision making process. When the owner has incomplete progress information, and the schedule constraints are poorly detected, communicated and managed, project delays are highly likely. In this research, 4D models and some concepts from the Last Planner System (LPS™) such as lookahead planning and constraints analysis were used in order to propose a "BIM-Lean" planning approach. Thus, the identification and communication of project constraints is enabled within the project team, so they can be adequately managed. This research aimed at improving the stakeholders understanding of the project progress and planning reliability. The renovation of a shopping center, which remained operating during construction, was used as a case study. This case study allowed the project planning and progress control procedures to be assessed and the proposed planning approach to be tested. The final version of it was validated in a Charrette test conducted with both project professionals and civil engineering students. This Charrette measured the participants' understanding of the project progress and constraints management information with and without the proposed planning approach. The results showed that the planning approach improved the understanding on project progress and owner's constraints management, which was particularly valued by site professionals and owner representatives.