BIM and Project Planning (1-2-3 Revit Tutorial)28 Feb, 2007 By: AIA ,Kenneth H. Stowe,Rick Rundell
BIM linked with project planning enables 4D construction planning.
Gantt charts have long been a staple of project planning, but they leave something to be desired when it comes to visualizing a project schedule.
Most builders invested in their first project planning system more than a decade ago, and they've become a vital tool for project management services. BIM (building information modeling) solutions, on the other hand, are relatively new. Rich with information, architects are using BIMs for all sorts of design-centric tasks -- energy analysis, sun studies and specification management to name a few.
Given the success of BIM in the design realm, building firms are turning to BIMs for their own uses, such as constructability analysis, trade coordination, clash detection, quantification and cost estimation. One of the most obvious building applications for BIM is where design and construction first come together: construction planning. This month's "1-2-3 Revit" column focuses on how BIM and project planning solutions can be linked to better present and analyze a building design throughout its construction.
4D Construction Phasing
Construction planning is an ongoing effort to manage the progress of a construction project and react accordingly -- dynamically adjusting to the situation on the ground. Of course, a building's design is at the core of its project plan, and by including schedule data in a BIM you can use BIM for 4D visualization, in which time is the fourth dimension.
4D models include planning data such as the start and end date of a component and their criticality or slack. As a result, using BIM for 4D visualization provides an intuitive interface for project team and other stakeholders to visualize the assembling of a building over time. It enables 4D construction simulation -- a key planning tool during preconstruction to evaluate various options. 4D storyboards and animations make it a powerful communication tool that gives architects, builders and their clients a shared understanding of project status, milestones, responsibilities and construction plans.
Teams usually start out developing 4D models by manually mapping the schedule dates from the project plan to the model components. That effort helps them improve the plan and improve how they communicate the plan to the whole team. Later, as they advance their skills, they programmatically link the schedule to the model to save time and increase their ability to evaluate various construction sequence options.
Below are two representative approaches for linking a BIM to a project plan. The first example features a direct link between Revit and MS Project, developed by Autodesk Consulting. The second example is a tool from Innovaya that exports a Revit BIM and displays it in a specialized 3D/4D visualization environment linked to a project plan from either MS Project or Primavera.
Direct to MS Project
Our first example features a software tool, developed by and available from Autodesk Consulting, that uses a bidirectional link between Revit and Microsoft Project to keep the project up to date when changes are made in either program.
The tool includes a new Revit function, Export to MS Project, that exports applicable building components to a MS Project file, presorted by level and category (such as wall, window and column) for rapid project scheduling and resource tasking.
Autodesk Consulting's Bidirectional Link with Microsoft Project tool links Revit Building components to a Microsoft Project for schedule creation and resource assignments.
In turn, the MS Project plan can be saved (as a standard MS Project MPP file) and used to update the BIM via a new Import from MS Project Revit function. This updates the attributes of affected Revit components with the start dates and finish dates from the MS Project plan. Note that the tool can be customized by Autodesk Consulting to include any other MS Project variables as needed. Planning information then can be visualized in Revit by filtering on this attribute data. For instance, users can ask Revit to show all the building components scheduled to be installed by June 1 or all components that will be worked on in October.
The bidirectional Revit to MS Project link updates Revit components with Microsoft Project details.
In addition, the phase information of Revit model components can be updated from the MS Project file, which allows Revit phase assignments to be automated via MS Project. For those readers unfamiliar with Revit phases, they represent distinct time periods in a project's life: existing conditions, first-floor new construction, phase 1 and first-floor new construction, phase 2, for example. Each building component can be assigned to a phase. To visualize how a project appears during the various stages of work, users toggle phases on and off. For example, users can ask Revit to show only existing conditions and first-floor new construction, phase 1 components. Or show all components in all phases, but highlight first-floor new construction, phase 2 components in red. A component's phase is passed to MS Project during the export process, and if that phase is changed (or added if the original phase was blank) in MS Project, the Revit model is updated during Import from MS Project.
Project Planning for an Integrated Workforce
Not surprisingly, one of the first customers to use the Revit/MS Project tool was a firm with a keen interest in planning and scheduling for its integrated design/build workforce. Dal Pos is 30-person architectural firm located in Syracuse, New York. Already an experienced Revit user, Dal Pos began using the Revit/MS Project link on a high-end multimillion dollar custom home slated for construction this year -- both for the benefits it would bring to that project and as a test case for future high-profile commercial projects.
According to Scott Bloss, senior BIM technologist at Dal Pos, "We began by exporting our Revit design model to MS Project and developing an initial project schedule. Now we regularly update the project plan from our design model and, in turn, push our planning data from MS Project back to Revit." The bidirectional integration between design and planning has improved communication for the whole team. This improvement is particularly evident at their weekly project meetings, in which the team can now see their upcoming construction tasks.
"We use scope-of-work filtering techniques within Revit to visualize the project plan," explains Bloss. "For example, I'll display all work items scheduled to be installed next week, or all components in a tight area color coded by trade, or highlight in blue all the items that are scheduled to be installed by a particular fabricator."
Dal Pos' use of the Revit/MS Project link has certainly improved design and construction coordination, but it's just one piece of a bigger strategy -- to create a completely digital job site with a building information model as the centerpiece. As Bloss puts it, "4D BIM is a must-have tool in our digital gangbox."
Our second example features a product from Innovaya called Visual Simulation, a 4D planning and constructability analysis tool that allows a BIM created in Revit to be integrated with either a MS Project or Primavera project plan.
Like Innovaya's Visual Estimating product that I cited in my August 7, 2006, article on BIM and Cost Estimating, Visual Simulation uses the Revit API to export the Revit model to the Innovaya file format. The model can then be imported into Visual Simulation. The product includes a specialized 3D/4D environment for both standard 3D building model navigation as well as 4D visualization.
Visual Simulation from Innovaya is a 4D planning and constructability analysis tool that lets users integrate a Revit BIM with a MS Project or Primavera project plan.
Early project plans can be developed directly in Visual Simulation by using Revit phases to generate construction-sequenced tasks based on hierarchical building components. Tasks created by this approach are automatically linked with the BIM objects, and this process can be completed very easily and quickly without requiring a schedule. This ability is particularly useful in the early stages of design, when project planning is rudimentary with perhaps just a few key milestones established.
As the project moves forward and the need for detailed project planning arises, the product also features a link to both MS Project and Primavera with import, export and synchronize functions. When a project plan is established in Visual Simulation, users can visually associate model objects and scheduled tasks. For example, users can click on a building object in the 4D visual environment and see its associated task highlighted in the Gantt chart or vice versa. Users can explore scheduling what-ifs by changing the start date of a task in the Gantt chart and seeing the ripple effect in the 4D model.
The 4D visual environment includes a variety of time/schedule filters for viewing building components based on construction type (that is, new, temporary, existing, etc), resources, start/finish dates, criticality, linked/unlinked tasks and so on. This ability allows users to do things such as highlighting potential installation issues (any building objects that are linked with two tasks on the same day are shown in red) or creating installation sequences of building components that can be animated and saved and then played back like a movie to show project teams or clients how the project or a particular area will be built.
Visual Simulation's 4D environment allows users to visually associate building model objects and tasks.
BIM for 4D Visualization Is a Reality
When firms begin to use BIM for 4D visualization, they usually start with the phasing capability inside of Revit, which can be used quite effectively for broad-brush construction visualization. As expertise with 4D modeling grows, users tend to use direct links between the BIM and their scheduling system by using some variation of the approaches presented above.
Whatever the path taken or technology implemented, BIMs that contain detailed schedule and resource data from the native project planning software are a reality -- and can lead to a more engaged team, more informed decision making and better coordination between designers and builders; resulting in smoother running projects built according to their schedule.