Biology of an Elephant - Creating Project Models from the Facility Model

A long time ago, in a blog post far, far away I wrote about a way of creating and managing multiple Project Models from within a single Facility Model. Since that time, I've had some opportunity to put that process into extensive practice and to refine it. Now that it has had some field testing, going all the way through several projects, here is the resultant process.

First, let's define some terminology:

Facility Model(FM) - this is the base model that the owner maintains for their ongoing use.

Project Model (PM) - this model is the slice, or plug, of the FM that the project team will do their design work in.

Before starting anything, archive a copy of your Facility Model (FM) using whatever method you prefer. Always back up your FM before major changes. As always, remember to save regularly.

Define the project scope within your FM. A mass works, so does a set of drafting lines or even just eyeballing it. 

Create a Project Model (PM) Workset for the project scope and put everything into that Workset. Creating a Model Group is something you do by selecting a large number of elements and then creating the Group. Once you create the Group, you can only add elements one at a time. A dedicated Workset will give you a simple way of grouping model elements that you can control visibility of easily until you are ready to create the Model Group. It also gives you a dedicated Workset for the linked model once it is ready for use downstream.

Select all of the model content within the defined scope and move it to your PM Workset. Keep in mind, the project scope might not include every piece of equipment in an area, for instance a project may only be for electrical systems remodel, or may include a number of pumps in a group of pumps, but exclude one that was just replaced. 

In MEP, this will make your connected systems disconnected. You can just accept that they are going to be disconnected or you can add a dummy load. One day Autodesk will allow us to connect loads across linked models, but we're not there yet. 

Some elements may need to be sliced or cut up in order to appropriately fit in the group appropriately. For instance, a wall may need to be cut, or a floor or roof. A 2100 square foot renovation that will include floor penetrations should include the floor, but it doesn't need to have the entire floor plate. Add these elements to the PM Workset. 

Look at your PM Workset in isolation to make sure nothing is poking out. Then do the inverse, looking at everything except the PM Workset to make sure nothing was left out. 

Rooms and Spaces are problematic. You can include them in the Model Group you create, but when you do, their Number value will get reset. I've worked with two solutions to this, the first is to copy the number to a new parameter with a Dynamo script, and then later copy it back when appropriate. Alternately, I have kept all of the existing rooms in the FM as a reference and the consultant creates rooms for the new areas only. Both approaches can work depending on your needs, for me, I keep the rooms in the facility model, there is more value to me as an owner there.

Levels will come over automatically with anything that is hosted to those levels. Gridlines can be copied over or not. I prefer to keep the gridlines in the FM and for the PM to reference those as part of the background.

Once you are certain you have everything in the PM Workset, select it all and create a Model Group. Once again, look at your model group in isolation, and then do the opposite, looking at everything except the model group.

When you are confident you have everything, select the Model Group. On the Modify Group tab, click on the Link icon (oddly enough, there is a default keyboard shortcut for this: “LG”). This creates your new linked model or Project Model (aka PM). 

The new PM will set all of the content to the New Construction phase, so don't freak out if everything disappears on you, you can clean that up in the new model. Save your current model, close it, and open the new PM. 

When the PM is created, there is a lot of information that isn't brought over from the old FM. There are two ways I have found for dealing with this. The first is to take your Template file, open a copy of it, link in the PM and Bind that link into the Template. Once it is bound, ungroup it and you are ready to go with your sliced model content and your default template content in one PM.

The second approach is longer and manual. I won't cover it here and now, but will have it in a later post, it's that tedious.

Enable Worksharing and create Worksets as you would in any new project. 

In the Phases menu, merge the New Construction phase, which has all of the existing content, into the Existing phase, where it most likely belongs. Then create a new phase for the project work, you can call it New Construction, though I prefer to name it according to the project for ease of mapping in the Facility Model. 

Link in your FM (it would be nice if it was automatically linked, but it isn't), and Copy/Monitor any levels or gridlines that didn't carry over automatically from the FM that may be appropriate to have. Acquire coordinates from your FM as well.

Save and close the PM, then open your FM.

Check your links to make sure you are linked to the new version of the PM. Map your Phases, and set the linked PM to Room Bounding (if appropriate).

With that, your PM is ready to go to the Designer. Anyone who attempts to make changes in the FM will see a Linked Model in that area and know that work is happening there.  As the designer updates the PM, you will be able to see it reflected in the FM. 

When the project is complete, the PM is merged back into the Facility Model using the Bind Link tool. I'll cover that process in a later post, rather than make this one wholly unmanageable. 

The Elephant in the BIM Room - Maintaining a Facility Model

There's a great big elephant stomping around in the BIM room. Actually there's a small herd of them, but we'll focus on what is probably the biggest one.

How are facility managers supposed to manage the BIM (particularly the model) when projects start happening in their already modeled facilities?

Let's say you have a pump station on campus that needs an overhaul before {pick your own poop joke here}. In this case, managing the facility model is simple enough since the facility is small and the project covers the whole building. The owner sends the existing model off to the designer and contractor and the updated model becomes the new facility model. Nice and neat and not at all dirty.

Too bad the world rarely works that way for facility owners.

On the other hand, let's say you have six million square feet of airport terminal and concourses. At one end of the terminal, you have Joe's Pancake Hut going into a tenant space. Nearby, City Airlines is moving into a recently vacated ticket counter area. At the other end of the Terminal, a new expansion has begun to add capacity. In between them, you have renovations in mechanical spaces to upgrade failing systems. Meanwhile you need to renovate airport office space for the folks who keep the airport running, while TSA also wants a new break room and locker facilities. 

All of this is going on with different start dates, end dates, delays, consultants, contractors, project managers and varying levels of quality to the existing As-Built condition. As the multitude of projects proceed, somehow it all gets juggled and managed and kept on track and executed to the owner's exacting design and BIM standards.

However, at some point, each of these projects has to come back in sync with your existing Facility Model, which is also being updated as maintenance chugs along on the building and stakeholders throughout the airport authority ask for exhibits, maps, diagrams, areas, adjacencies and all sorts of other data on existing and future conditions.

Does this even work? For the love of BIM, HOW!?

The answer may lie in a little known, seldom used functionality within Revit. In fact, it's obscure enough that it doesn't even get a mention in the Mastering Revit Architecture books.

Convert Groups to Linked Models

In this post we'll cover the general gist of working with this tool, in a post in the near future I'll go through the more technical steps and things to watch out for. 

How it works, for a facility owner, is that you establish the scope of a project within the model. This probably means slicing walls and cutting up floors. 

Select all of the content in that scope and create a model group from it. Some content, such as Rooms and Spaces, cannot be placed in a model group, so those will have to be addressed separately.

On the Modify | Model Groups tab>Group panel there is a small Convert to Link icon. Revit then gives you two options, Replace with a New Project File or Replace with an Existing Project File. The first option is the one you want, it creates a new Revit file with just the content from the model group within it. 

In your facility model, you'll find that the model group, which had replaced integrated content, has itself been replaced by a Linked Model. 

When you open the new Revit file, you'll find only what was in the model group, so you will need to Transfer Project Standards from a fresh file and copy in your base family content. 

Send the file off to your consultant. As they do their work, you can update the link in your base facility model with their project model. If you have multiple projects going on in your facility, you can see how they are integrated over time via mapping each project to a phase in the facility model.

The content in that area being a link tells anyone who goes to use the Revit model that the area in question is effectively off-limits and they need to coordinate with the project team if they are going to change anything.

When the project is complete, use the Bind Link tool to integrate the project model back into the Facility Model. You're then left with a whole, current, living Facility Model. In fact, during the entire process, you never stop having a living Facility Model.