Indoor GIS: Keeping Your CAD/BIM Data and GIS Data Synchronized

JASON HINE: Hi, everyone. Welcome to this industry talk titled indoor GIS, keeping your CAD and BIM data and GIS data synchronized. My name is Jason Hine. And I'm a senior product engineer with the ArcGIS indoors team at ESRI. Here's our agenda for the hour. We'll start with a very quick refresher on indoor GIS before we jump right in and start exploring the four phases of the indoor GIS data life cycle. We'll close out the talk with a summary of key points and takeaways.

Before we begin, I'd like to briefly draw your attention to the safe harbor statement displayed here. Over the course of our time together, I'll be talking about versions of ArcGIS Pro, ArcGIS Enterprise, ArcGIS Online, ArcGIS for AutoCAD, and possibly other software or other products that are not yet released. And I'll also be mentioning some of ESRI's future goals and plans. So this is just a legal disclaimer that any forward looking statements I may make are just that, forward looking, and subject to change. That said, let's proceed with the presentation.

To start, let's review what an indoor GIS is. A Geographic Information System, or GIS, is a system of geospatial applications, tools, and workflows, designed to create, manage, analyze, and map spatial and non-spatial data in a geographic context. So an indoor GIS brings all the abilities of a GIS to bear on indoor spaces.

For example, we can create beautiful, floor aware maps of building interiors, manage asset and floor plan data, conduct space usage analytics, and get directions between indoor locations, and use the blue dot to track progress along indoor routes. ArcGIS Indoors is ESRI's comprehensive indoor GIS providing robust data models, tools for data creation and management, developer tools, and a collection of focused apps to help you build out your indoor GIS.

The data that powers an indoor GIS moves through a life cycle with four phases, model, load, share, and maintain. This talk is focused on the maintain phase. And I'll be showing you tools and workflows to manage updates while preserving the business data in the GIS and the integrity of your CAD or BIM floor plans.

The model, load, and share phases come first. And there are decisions to be made during those phases that can affect how we maintain the data. This is especially true when it comes to the initial loading process. So we're going to go in order model, load, share, and then maintain. But we'll keep the first three light, brief, and focused on how they relate to data maintenance.

So let's start by talking about the data model for an indoor GIS. We're going to look at what ArcGIS Indoors uses for its core data model. And you can certainly roll your own if you want. But I'd recommend adopting this model if you can. It's already been tried and tested. It's well documented. And it's extensible. So you can add whatever data you want to the model. By the way, if the QR code disappears before you can scan it, don't worry, codes and links will be provided again near the end of the presentation.

We'll start with the largest features in the indoor GIS model, sites. The ArcGIS Indoors model has a Sites feature class with polygons that represent the geographical areas where our buildings are located. On this map made with ArcGIS Pro 3.1, we see some of the esri corporate sites in Redlands, California. And that control in the top right corner of the map, that's the floor filter, which works with this data model to allow the user to drill down into the indoor map.

Next in the data model is the Facilities feature class, with polygon features that represent building footprints. And then a Levels feature class, with polygons representing the footprint of each floor in our buildings. Notice how the floor filter makes it easy to drill down into the data.

The last feature classes we'll consider today are the Units feature class, with polygons representing the rooms, hallways, and other traversable spaces on each floor, and the Details feature class, with polylines representing walls and doors, windows, and other parts of the architecture. Each feature class in this hierarchy has ID fields that let us relate details and units to a level, levels to a facility, and facilities to a site. These IDs enable what we call floor awareness in the GIS. And we'll be relying on these IDs when it comes time to maintain the data.

In ArcGIS Pro, we can configure a map as floor aware by indicating which map layers represent the sites, and facilities, and levels. And then we can configure the units, details, and other layers in the map as floor aware by indicating which attribute field contains the level IDs. Once the map is floor aware, we can use the floor filter to navigate the indoor map.

So next, let's talk about tools to generate an indoor GIS schema. In ArcGIS Pro 3.2, ArcGIS Indoors has several geoprocessing tools to create feature data sets that support different indoor GIS use cases, including 2D maps, 3D scenes, and indoor routing. Please note that you don't have to use these tools to create your indoor GIS schema. They just save you time and effort, establishing the feature classes and attribute fields needed for most indoor GIS applications.

Another way to generate an indoor GIS model is by using ArcGIS for AutoCAD, ESRI's free plugin for AutoCAD users. ArcGIS for AutoCAD includes an indoor data set template you can add to new or existing drawings. I'll show a quick demo to illustrate.

Once we've downloaded and installed ArcGIS for AutoCAD from ESRI's website, we can access the indoor schema template from the ArcGIS ribbon under Add Data, Create. There are many templates here for all kinds of use cases. And the indoor data set template generates feature layers and associated CAD layers for the sites, facilities, levels, units, and details feature classes with standard attributes from the ArcGIS Indoors information model.

OK, so now that we've got a data model for our indoor GIS, we can load it up with data using this basic workflow. First, we'll want to make sure-- we'll want to check our source CAD or BIM to make sure it's in good shape to load. And then we'll use some tools to help load our data into the indoor GIS. And then we're going to talk just a little bit about quality control. As we talk about these things, consider how they're also going to play into the maintenance phase.

The data sources we're talking about loading today are CAD drawings and BIM models. There are other potential floor sources, such as PDF files and reality capture data that ESRI is aiming to support in the future. But those are outside the scope of this talk.

As we get ready to load our CAD or BIM into the GIS, we need to be mindful of their differences. For example, CAD and BIM typically use a local Cartesian coordinate system where middle-- for example, CAD and BIM typically use a local Cartesian coordinate system, where millimeters matter. While GIS data typically uses map projections, where being within a few centimeters is usually considered quite good.

Another difference is that CAD and BIM are primarily concerned with modeling the building's architectural materials. While indoor GIS is more concerned with the spaces, like rooms and hallways, and how people and assets are positioned and moving through those spaces. Yet another difference is that CAD floor plans tend to use separate text objects to store information like room numbers. While in a GIS, each feature stores that kind of information in its attributes. These and other differences can have big implications whenever we're loading or maintaining our data in the indoor GIS.

We also wanted to check to make sure our CAD or BIM data is ready to go through the loading process. We want to ask questions like, is it complete and up to date? Will it work with the loading tool that we want to use? By which we mean is our source data organized into categories, layers, or properties that the tool can work with? Does the geometry in our data meet the tool's requirements to build polygons? And does the text or properties in our data meet the tool's requirements to populate attributes?

With regard to these questions, BIM data generally scores better. And CAD data generally scores worse. I found that CAD floor plans that are just fine for construction design often have conditions that can cause problems during loading into a GIS, including small gaps and missing or incorrect room information. The eagle-eyed among you may have noticed a couple of these conditions in the data seen on the slide.

To help detect and find such conditions, we've developed an indoors extension to our ArcGIS for AutoCAD product. This extension is designed to save you time finding small gaps, missing information, and other conditions that can impact the loading process. First, I configure which layers of my drawing have the entities that form unit boundaries. And I can also configure the extension check for missing or non-unique unit names or unit use types. And I can configure a list of standard use type values for it to check as well.

After configuring the Indoors extension, I can run its validation checks. The Indoors extension analyzes the entities on the configured layers for any conditions that can cause data quality issues. Results are displayed on a separate layer and in a dockable, interactive window. I can filter and click to review the results and decide whether and how I want to address them. Remember, I'm responsible for maintaining the CAD floor plan's integrity.

I can find the closed small gaps that would cause unit spaces to import incorrectly. And could find and correct cases where unit names or unit use type information may be missing or incorrect. The Indoors extension is being released with ArcGIS for AutoCAD version 430, which again, you can download for free from the ESRI website.

So once our source data is ready to go, we're going to want to use some sort of ETL or data conversion tool to load it into the GIS. If you're familiar with FME, they have readers for CAD and Revit files. And you can use their ETL tools to automate many kinds of data loading scenarios.

ArcGIS Indoors, on the other hand, provides tools specifically designed to load CAD and BIM floor plans into the ArcGIS Indoors information model. These tools give you control over feature extraction and attribute mapping with default settings you can customize for the job at hand.

With the release of ArcGIS Pro 3.2 this fall, there are two new tools, an import CAD tool that works faster and gives you even more control over feature extraction, and a new tool for importing floorplans from IFC files. We'll be referring to data loading tools again later when we're talking about maintenance. The takeaway here is whichever tool you choose to load your CAD or BIM into your GIS, make sure you understand what the tool requires of your CAD or BIM data. And then check that your data meets those requirements.

Now that said, no matter how carefully we vet our source data, there's still the possibility that something goes pear shaped during loading. So we'll want to do some quality control to make sure our GIS data is complete and correct. ArcGIS Indoors provides built-in attribute rules that work with ArcGIS Pro's error inspector to check for common types of geometry and attribute data issues.

And you can extend them with additional rules specific to your use cases. Even with the automated checks, though, I still manually spot check a few features in each feature class to make sure they have the geometry and attribute values I'm expecting. In particular, I like to select complex unit features such as large lobbies or looping corridors and see if the selection has the shape that I expect.

I'll also spot check a few values in the name, use type, and any other mapped attributes to make sure the information was mapped correctly. So once we've loaded our indoor GIS with data, we can proceed with other setup tasks like generating indoor maps, setting up an indoor routable network, and so on.

For the purposes of this talk, we're going to skip over that stuff. But we need to at least touch on the topic of sharing our indoor GIS data because how we choose to share our data has a lot to do with how we'll be able to maintain it as changes occur over time.

When it comes to how indoor GIS data is shared, there's a lot to consider. And we're just going to touch on a few things here. A good place to start is to think about the people who need access to the data. Are your end users students trying to find their way across a college campus? Or are they emergency personnel rushing to a crisis? There might be managers who need secure access to sensitive employee data or space planners who want to run what if scenarios. Make sure that the sharing mechanism you choose has the security and flexibility that you need to support all your users.

What apps will those users be using when they access the data? How do those apps control access? Do the apps have any functional requirements for how the data is shared, such as the ability to track edits or to access individual feature layers?

And it's also important to take time, and identify, and make plans for any editing scenarios you'll need to support. Are the editors all within the organization? Or are they distributed across multiple organizations? Will editing be done by one person at a time? Or will multiple editors be making edits concurrently? Do your editing workflows require versioning, so that changes can be reviewed prior to merging with the production data?

There's a lot more we could talk about here. But for the sake of time, we're just going to take a quick glance at a few possible sharing models. First up is ArcGIS Online, ESRI's cloud-based SaaS solution. ArcGIS Online supports sharing indoor GIS data products, including feature layers, 2D web maps, and 3D web scenes. We can publish indoor maps directly from ArcGIS Pro or just publish the individual feature layers and use ArcGIS Online's map viewer to build our indoor web maps in the cloud.

As long as the core Indoors feature layers are present, our ArcGIS Online hosted maps and scenes can be made floor aware. ArcGIS Online also supports authenticated access with individuals and groups inside an organization, as well as anonymous public access. One maintenance consideration with ArcGIS Online is that because the published data in the cloud is a copy of the original data, we'll need to republish the data to push any changes out to our users.

ArcGIS Enterprise, on the other hand, is ESRI's full-featured software-based mapping and analytics platform. Among other things, it offers more flexible data storage and sharing options and better support for editing scenarios. For example, with ArcGIS Enterprise, we can directly publish a web map and associated features as a floor aware tile image service for fast access to large indoor maps.

ArcGIS Enterprise also supports branch versioning, a type of geodatabase versioning that works with ArcGIS Enterprise's web GIS model using a service-based architecture to allow multi-user editing workflows via web feature layers. More information about branch versioning is available from our resource pages.

And sometimes, it makes sense to use both ArcGIS Online and ArcGIS Enterprise. One example would be if we want to manage simultaneous editing with branch versioning while also publishing production data to ArcGIS Online for access by public users. Now, please note, I've just presented a few suggestions. Hopefully this high level overview gives you ideas as you think about what data sharing approach would work well for your organization.

OK, so now that we've touched on some relevant aspects of the model, load, and share stages of the indoor GIS data life cycle, let's talk about maintenance. We're going to talk about how we can maintain our GIS data by applying changes from updated CAD and BIM or from GIS data editors. And we'll also discuss how we can maintain our source floor plan data, using our GIS data as an informative overlay.

To get us started, here's a basic workflow for the maintenance phase. We covered steps 1 and 3 earlier when we were talking about the loading phase. So we'll focus on step 2 here. First, our maintenance workflow should preserve, as much as possible, the existing information in our target data.

For example, if only the shape of a room has changed, the corresponding unit feature's geometry and measurement attributes should be updated. But the other attributes for that feature should be left untouched. ArcGIS Indoors data import tools are designed with this in mind.

We also want changes applied in a way that maintains the integrity of the target data. If a door gets removed as part of an open space remodel, does that mean that the spaces on either side of where the door was should no longer be considered separate units? What about if there's a curved wall that was generalized in the GIS for faster display by web clients? Does that mean that the CAD drawings should be updated to match the generalization?

Quality control measures can help us here. But we want our maintenance workflow to minimize the risk of data integrity issues happening in the first place. We'll look at some more concrete examples of this basic workflow in a moment. First though, we should think about the organizational context in which this maintenance workflow will be taking place.

Earlier, we talked a bit about the differences between CAD, BIM, and GIS data formats. And when we talk about maintenance, it's important to recognize the different roles that each format serves within your organization. We need to think about how the data is used, and how those uses depend on the integrity of that data, and which people inside the organization are responsible for ensuring the data's integrity remains intact.

This diagram represents how CAD, BIM, and GIS typically fit within an organization. Where CAD and BIM as-builts are the approved and official drawings for design and construction aspects. And the production GIS supports the organization's management and operations aspects. Now, your organization might do things a little differently. But the point here is to have your organization's roles and responsibilities in mind when planning long-term maintenance of the data.

A related question is what data does the organization consider authoritative? For example, if my organization already has established standards, resources, and workflows around our CAD and BIM data maintenance, and if our GIS resources are limited, we might treat our CAD and BIM data as our single source of truth and only allow architectural changes to flow from there down to our indoor GIS.

Some organizations may be in the opposite situation, with a strong GIS department and limited CAD or BIM resources. In which case, they might opt to maintain the GIS as the authoritative and export the data to support AEC projects on an as needed basis. It's also possible for an organization to treat both as authoritative in their respective domains, with departments collaborating to synchronize maintenance changes in both directions. Let's take a closer look now at the workflows and tools available to support these scenarios.

So here's a workflow for data maintenance where the CAD and BIM data serve as the organization's de facto as-built record. The CAD department maintains the CAD and BIM data using established workflows. And the authoritative-- that authoritative data is then used to load the GIS, which is then shared and put into production. Now, when the CAD department produces official updates, we would use our maintenance workflows to apply the updates to the GIS.

What are those workflows? Well, if we used ArcGIS Indoors tools to import our CAD or BIM data, we can rerun those tools as part of our maintenance workflow. When the tool is able to match an incoming unit feature with an existing unit feature, geometry and attribute changes are applied selectively to preserve existing unit information and feature relationships, which helps maintain the overall integrity of the GIS data.

This next diagram depicts the opposite scenario, where the organization treats the GIS data as authoritative. The GIS department can use CAD and BIM archives as sources during the initial setup. After which, the floor plans are maintained through edits directly to the GIS data. Edits can be made using ArcGIS Pro or ArcGIS Online's map viewer. But not everyone is a GIS specialist, at least not yet. And so ArcGIS Enterprise 11.2, we're going to release a new Floor Plan Editor app for ArcGIS Indoors.

Floor Plan Editor gives managers and operations staff an easy-to-use web-based tool for basic indoor GIS editing. It includes customizable palettes of common floor plan components. And it works with branch versioning to support multi-user editing scenarios. Now, just to be clear, this tool is not designed to make architecturally accurate edits. That's what AutoCAD is for.

The purpose of Floor Plan Editor is to give regular staff the ability to make local, symbolic changes to the GIS floor plan to reflect the way the space is laid out and being used. Floor Plan Editor is scheduled to release with ArcGIS Enterprise 11.2 this fall.

Returning to the previous slide now, what can this organization do if they need up to date construction floor plans for an upcoming remodel project? As we've noted, the GIS data is well suited to support business operations, but not as well suited for architectural design and construction activities.

So when the organization contracts with an AEC company, the GIS department will want to provide the archived CAD and BIM files and also provide the GIS data for use as an overlay. The GIS data may not be survey grade. But it is the organization's most authoritative and up to date floor plan data.

One way to provide the GIS overlay is to export the relevant units and details features using the Export to CAD tool available in ArcGIS Pro. I'll demonstrate this in a minute. Another option is for the architect to use ArcGIS for AutoCAD to directly access the units and details feature layers in the cloud. In either case, the architect can overlay the GIS data onto the architectural drawings to see what floor plan changes may have occurred that could require new surveying.

All right, and lastly, here's what it might look like for an organization that wishes to maintain both the architectural and the GIS data. Unless one department owns all of the data, this will require some interdepartmental collaboration to keep everything current and minimize rework. The GIS department is responsible for managing edits to the GIS and communicating those edits to the CAD department. And the CAD department is responsible for incorporating the GIS changes into their redlining process.

At the end of each AEC project, the CAD department is going to provide updated as-built drawings to the GIS department for import. Now, of course, these workflow diagrams are very high level. And details will differ based on the scenario. And one scenario I get asked about a lot is how to handle it when the CAD and the GIS data are both in an edited state. So let's look at a concrete example.

Here, we see some indoor GIS data in ArcGIS Pro. The GIS department has made a few edits, seen here in a split view where the left side is before and the right side shows after. And there's a conference room here that was converted into two single office spaces. This involved splitting the unit polygon in two and updating the attributes. And a polyline was added to the details feature class to represent the imaginary boundary between the two offices.

One other edit here in the GIS, this door feature was updated to show that it really swings outward. The GIS department wants to communicate these changes to the CAD department. So that the source CAD drawing can be updated. Before we do that, though, let's look at the CAD drawing.

Looks like the CAD department undertook a small remodel project, where the shape of the receptionist area was changed to accommodate a second person. And a few new cubicles were constructed on the east side of the floor. The CAD department wants to communicate these changes to the GIS department. So that the data can be updated.

So how should these departments collaborate to apply the changes? The best practice here is for the GIS department to send the updated GIS to the CAD department first. CAD department can then overlay the GIS on the CAD floor plan and apply the GIS changes following their CAD standards and best practices.

Once that's done, the CAD department can send the updated CAD drawing with the GIS changes already applied back to the GIS department. And they will then rerun the same import tools they used during the load phase with settings adjusted to just load the floor of interest. Applying the changes in this order requires less work and helps preserve the business data in our GIS.

If we did it the other way around, the import tool would want to replace the two single units with the original conference room. And business information associated with one of the single offices would be lost. And the GIS specialist would need to resplit the conference room. So when there are changes in both data sets, the best practice is to apply changes from the GIS to the CAD first. And then apply changes from the CAD to the GIS. Let's do that now.

To transfer changes from the GIS to the CAD, we can start by making a selection in ArcGIS Pro that includes our updated units and details features. We can then use the Export to CAD geoprocessing tool to export the selected features to a new CAD drawing.

Switching to AutoCAD now, let's open the drawing we just exported. The drawing has these units and details layers with entities based on our GIS data. I'll change the layer colors to make them easier to see against AutoCAD's dark theme. As a CAD specialist, I'll copy and paste these entities into the source CAD drawing, using a common base point to help me align the data.

Now, this data happens to have the same orientation and scale as the drawing. But I could rotate the GIS data or scale it, if needed, to get it to overlay properly. Once it's lined up, I can modify the layer order, colors, or other properties of the GIS data. So that I can see where it and the original CAD linework are different.

Seeing that the conference room's been split, let's apply that change. Notice that the line from the GIS is shorter because the GIS generalized this curved wall. Now, I know gaps can cause issues during imports. So the safe route is to just draw a new line to create the two office spaces, making sure the line snaps to the correct entities at each end. That way, I can be sure that the line work adheres to our CAD standards.

All right, next, I see this door's orientation has been changed in the GIS. Now, my CAD standards state that each door in my drawing should be a block with a name that describes the door's size. The door polyline from the GIS doesn't have that information. So to preserve the integrity of my drawing, I'll just reorient the existing door block.

And I just remembered that I also need to update the text for the split conference room. The string values I need are in the exported GIS data. And I can use ArcGIS for AutoCAD's attribute table to find them. I just need to select the unit and open the table to see its GIS attributes. So I'm going to move the existing text into the correct unit and update the unit use type, and then do the same for the new unit.

Having applied the changes, I'll use ArcGIS for AutoCAD's Indoors extension to check if I missed anything. Now, the only results I'm seeing are ones I've already determined to be non-issues. So things look good. If desired, I can go ahead and remove the units and details layers. So they're not cluttering up the drawing before I send it back to the GIS department.

So let's switch over to ArcGIS Pro now. As a GIS specialist, I've received the updated CAD file. And I'm going to apply the changes to a branch version of the GIS data. So I can test and make any corrections before pushing the changes into production. Previously, I ran the Import Floor Plans to Indoors Geodatabase tool, which stores information about the source CAD in a configuration spreadsheet.

I just need to update a setting on the spreadsheet to make the tool process the one level that has the changes. Then I'll set up the tool and run it. My tool will update the geometry and core attributes. But it will leave intact the unit attributes that store our hot desk assignments, our room reservations, and our other business data. When the run completes, I can do my quality control checks on the branch version, make any necessary changes, and then merge it with the production data.

So again, the best practice in this scenario where both the CAD and GIS are in an edited state, is to first overlay and apply the GIS edits to the CAD and then re-import to apply the CAD edits to the GIS. Time for a quick recap of what we've talked about today. We've been discussing different aspects of the indoor GIS data life cycle.

We looked at an indoor GIS data model to gain an understanding of its schema for geometry and attributes. We saw options and tools to assist with loading source CAD and BIM into the GIS. We spent a few minutes talking about ways we can share the indoor GIS data. And we looked at considerations, workflows, and tools for long-term maintenance of our data.

Here are some of the main points I hope you'll take away from this talk. First, I hope you see how important it is to plan this stuff out in advance. There's a lot to consider at each phase of the indoor GIS data life cycle. And the choices you make in each phase can impact what choices are available to you later on. Involve the right departments and look for ways to fit in with their existing workflows. And come up with a repeatable data maintenance process that fits you and your organization.

Second, if you're just getting started, there's probably no need to reinvent the wheel. Take a look at the extensible ArcGIS Indoors information model. And if your organization has a lot of CAD expertise and not many GIS resources, consider using the ArcGIS for AutoCAD plugin to enable the CAD department to support more of the GIS data lifecycle.

Third, remember that data preparation pays dividends, not just during the initial loading phase, but each time you need to maintain the data as well. Check that your source CAD or BIM is organized and has the information that the import tool needs to generate feature geometry and attributes during the import process.

And here, finally, is a pro tip to close us out. If the GIS data has quality issues due to conditions in the source CAD or BIM, don't just fix the GIS data. Address the conditions in the source data. So that you don't have to keep refixing the same issues in the GIS each time you rerun the import tool.

As promised, here's that slide with the resource links. Other than that, thank you very much for attending this session titled indoor GIS, keeping your CAD and BIM data and GIS data synchronized. I wish you all the best.