3D models for constructability analysis, quantity takeoff, and model-based scheduling have been typically described as point applications. An integrated 5D system, where the 3D model drives quantity takeoff (along with model-based cost planning comprises the 5th D), which is automatically tied to a location-based schedule to generate resource and cost-loaded schedules (the 4th D), is a more novel concept. Integrated 5D approaches have been used in commercial applications since 2005 but there are only few case studies in technical literature to illustrate the benefits and challenges of implementation. The goal of this paper is to present the case study of Kaiser Oakland hospital project, the largest known implementation of integrated 5D systems combined with location-based planning. We analyzed specifically the preconstruction phase of foundations. The benefits of the 5D system were studied with the following hypotheses based on the experiences gained in previous projects. First, model-based constructability based on a parallel construction model should identify more constructability issues than traditional model-based constructability processes. Second, model-based quantity takeoff should take less time than manual take-off. Third, integrated location-based scheduling should enable schedule optimization over CPM–based approaches, resulting in shorter overall duration with more continuous resource use. Two out of three hypotheses were supported in the preconstruction of foundations. First, over 200 additional constructability issues were identified using the construction model. Second, Location-based scheduling enabled the planning of continuous work for subcontractors while compressing the duration of Foundation phase by six weeks. Contrary to the hypothesis there was no time saving benefits related to quantity takeoff, although there were some qualitative benefits in terms of better communication.
Location-based management, constructability, 5D model, flowline schedule
Kala, T. , Seppanen, O. & Stein, C. 2010, 'Case Study of Using an Integrated 5D System in a Large Hospital Construction Project' In:, Walsh, K. & Alves, T., 18th Annual Conference of the International Group for Lean Construction. Haifa, Israel, 14-16 Jul 2010. pp 664-673