BIM-Based 4D Modeling and Scheduling - Construction Project Scheduling and Control - page 398

both the design and construction phases. Thus, the probability of having change
orders, rework requests, and time and cost overruns during a project is minimized
prior to the initiation of the construction. Also, through the generation and utiliza-
tion of 4D models, project managers and contractors can determine site management
facilities (i.e., site layout planning), coordinate subcontractors and suppliers, plan site
logistics (i.e., access routing to the construction site), and communicate concerning
the completed parts of the projects with the different subcontractors.
Steps for Creating 4D Models
The steps for creating the 4D modeling process in BIM are as follows:
• A 3D model of the building should be developed using a design authoring
software (such as Autodesk's Revit, Nemetschek's Allplan, etc.) to create the
intelligent objects and appropriate groupings of the construction components.
Construction components should be created based on hierarchical groupings so
that a construction schedule can be easily linked to the 3D model. During the
development of the 3D model of the building, the involvement of the contrac-
tor is essential, because the contractor can provide rapid and reliable feedback
about the sequencing, constructability, and sustainability of the building. The
“selection tree” should be developed based on the work breakdown structure
(WBS) of the building component and the project schedule.
• A project schedule should be developed using compatible software such as MS
Project or Primavera P6, manually keeping track of the project tasks within the
Navisworks TimeLiner. The project schedule should be developed based on the
consideration of the sequence of activities and the logical relations among them.
Refer to the previous chapters for an examination of how to create a project
schedule.
• The project schedule and 3D geometry of the building component should be
imported to the Navisworks TimeLiner, and the project tasks should be linked
to the relevant 3D objects by using “selection tree.”
• Once this linkage has been done, a 4D model can be generated that shows
a movie of the construction of the building, representing how a building is
constructed over time, step by step. The work flow for creating a 4D model of
a building component is given in Figure 15.5.
Various BIM tools can be utilized when you are creating a 4D model for a project.
The most common commercial BIM tools that have the ability to create 4D models
are given in Table 15.1, along with their descriptions. In almost all of them, the way
to import the model or a schedule differs, but the concept is the same.
Definition and Benefits of 5D Modeling
5D modeling is the integration of 3D models of a project with cost and time asso-
ciations. While 4D models add time- and schedule-related information into the 3D