Revit MEP: Six Steps to a Sturdy Foundation

September 25th, 2012

It’s not uncommon to hear the outburst, “I need more RAM!” Truthfully, it’s more than RAM that should be considered, even though RAM seems to be the culprit when waiting for a Revit screen to refresh after a command or save to Central.  It’s no secret that Revit has hardware requirements, but often overlooked are things such as project setup, worksets, efficient family content, worksharing monitor, and so on. These are all part of the process of managing a Revit MEP project.

It is true that developing and maintaining an efficient Revit MEP model can be a daunting task, but taking time up front can alleviate most of the pain encountered.  One of the major keys to having a successful Revit MEP project is to understand the setup and structure of a project.  Just like a building, projects must have a sturdy foundation. To have an efficient and consistent model with good performance from beginning to end, the initial steps are crucial to start it off properly.

Step One:  Appoint a model manager for the project.

Regardless of your firm’s size, it is important to designate one or two individuals responsible for setting up and maintaining an MEP model. Their role should include, but not be limited to, setting up the model, setting up worksets, compacting and auditing models, reviewing warnings, purging linked models ( if they are static), and updating linked files.  A model manager is the go-to person when one hour from printing a change is about to occur within a linked architectural model. The model manager knows the setup and structure of the MEP model and can make the necessary changes to get the project out in time. Now that a team has been developed the process of setting up the MEP Model can begin. 

Step Two: Determine the project or building type. 

Be aware that projects such as health care facilities can require more computer resources and management because of the number of MEP systems that are modeled within this type of facility. Compare this to a multi-story office building or Industrial building that may have a similar square footage but not as many MEP systems.  It is often too difficult to relate a Revit files size to a buildings square footage for the above reasons.  As a company, be sure to monitor file sizes and develop a standard for splitting up models and worksets.

Step Three: Enable worksets.

Whether working in the same model or within separate discipline models, enabling worksets can be very beneficial to the project.  Worksets can be thought of as another level of visibility management in which we can select any combination of elements and group them into a workset and have control over whether or not Revit will display them. Worksets also give the ability to maintain the long-term performance of a project while easing control when coordinating levels and grids between architectural and structural disciplines. More detail on this later.

To enable worksets, navigate to the Collaborate tab and select Worksets.  The Worksharing dialog box will appear.  At this point Revit offers two different worksets—one for shared levels and grids and the other for the remaining elements within the project.   Worksets can be renamed at this point but it is not absolutely necessary to do so.  Select OK.   Be patient—it will take a minute for Revit to rewrite the project data base to enable worksharing and for the Worksharing dialog box to appear. 

Once the worksets dialog box appears worksets can be created.  In this case, a workset for each discipline, one for each of the linked models, and a workset for Shared levels and Grids is created from each linked models from the Architectural and Structural projects.

Step Four: Leverage worksets.

After the necessary worksets have been created select OK and save the project as a central file. In the Save As dialog, select Options and then select Specify under the Open Workset Default.  This will bring up the worksets screen prior to opening your Revit file, which will give you the ability to choose the worksets when opening the project. This can potentially decrease the amount of time Revit takes to load a project. After saving the project as a central file be sure to go back into the worksets dialog box and select “No” under the “Editable” column to make the workset non editable. 

Step Four: Use element borrowing.

It is good practice to use element borrowing instead of making the entire worksets editable.  There are situations where a user might want to make a workset editable and, therefore, takes ownership of all objects that belong to that workset.  The trouble is that no one will have access to any elements within that workset until that workset returns to a borrowed workset.  Using element borrowing is as easy as not checking out any worksets. With no workset checked out, any accessed elements are borrowed from the workset, leaving the rest available to other users. It is important for users to set the appropriate workset when introducing new elements to the project and to Sync to Central often to release the borrowed elements.

Step Five: Manage worksets.

Worksets are meant to be flexible. They can be added, deleted, or renamed at any time during the project. Within the worksets dialog box, users can choose whether or not the workset is “Visible in all views.”   In most cases worksets should be visible in all views.  One example of deselecting “Visible in all views” may be an existing DWG file that is being used for a demolition plan and should only be visible within that view.  In that case, deselect “Visible in all views” and from Visibility/Graphics Overrides within the Demolition view, turn that workset visibility on.  It is good practice to use this technique when importing a file that is only visible in a few views.  There is a potential increase in performance because Revit is not refreshing that DWG file in every view.

Step Six: Associate worksets with linked files.

After linking in the appropriate Revit files make sure to select the linked file in plan view and choose the appropriate workset within the instance properties and type properties.  Below see the link is now associated to the “Linked Architectural Model” workset within the MEP model.

This gives the ability to control the visibility without actually unloading the linked file. On the Manage tab, select the Manage Links tool to control the linked file worksets.  In this example the user can choose to close or leave open the Exterior Shell, Furniture, Interior Space, Linked Models, or Structural Grids within the “Office Building.rvt model.”  

The ability to control the linked files worksets can be very beneficial for not only performance, but also for visibility graphics control.  For instance, using worksets will allow the control Levels and Grids between Structural and Architectural Models.  In a common workflow the architectural model gets grids from the structural model.  Conversely, the structural model gets levels from the architectural model.  MEP gets levels from the architectural model and grids from the structural model. 



The ability to control the levels and grids between the architectural and structural models is beneficial when managing grids and levels between multiple links.

There are a number of ways to use worksets.  Technically one workset would be enough for Revit to function, but using several will enhance the performance and flexibility of the model.  There is no hiding that multiple worksets can get confusing, so carefully consider how they should be used project by project.

Considerations

When determining how to use worksets, consider the makeup of the team.  If there are multiple engineering teams working on a project, worksets by team may best accommodate the project requirements. This allows individual teams’ worksets to be loaded or not loaded which will lead to increased computer resources and eliminate teams from working on top of each other. This requires a comprehensive coordination plan.

Splitting worksets by disciplines can benefit offices that work within the same model. In addition, separating the engineering systems can be useful. Electrical engineers can control the display of HVAC and plumbing separately or the display of mechanical equipment requiring electrical hookup separate from mechanical equipment that does not.  This will speed up and increase performance within the model. 

Projects that contain multiple areas, levels or a campus of buildings are all great candidates for worksets. Separating the building areas, levels, or buildings will optimize work on larger projects and multiple systems within the same MEP Model.

As projects evolve from schematic design to construction documents the files size can grow over three times. These are just a few ways to manage a Revit MEP project to maximize speed and build predictability. The options for individual firms are complex and endless, but making the effort to coordinate and agree on the best procedures and practices will allow firms to be more consistent and productive. This will not only affect the project over time, but it spans projects, teams, and geography.  Maybe some more RAM would be nice, but addressing options to increase productivity efficiency and managing a project better is far more beneficial than simply adding RAM to PCs.

John Shelbourn is currently the BIM MEP Manager for Leo A. Daly. John has been working with Revit MEP since 2008 and has prevous experience with many different Autodesk products including AutoCAD, Autodesk Building Systems, 3ds Max, and Navisworks. He has been the guest speaker at the Revit User Group of Nebraska. Being an early advocate of Revit MEP, he continues to support the process behind Building Information Modeling.

 

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John Shelbourn

 

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