What is data-featured image

What is data? Introduction to Data Management in BIM

In my day-to-day job, as a Digital Collaboration Coordinator, I spend many hours collecting, checking and managing various kinds of BIM data. Far too many times after receiving a set of data I threw up my hands helplessly – the quality was far below the point I could use it. Then I would start a mundane process of data cleaning. I cursed this situation countless times before it struck me – most of the people on the construction project don’t even know how to handle data correctly! We have never been taught what makes for a good data set. Neither how to fill Excel spreadsheets to allow easier data management. Nor how to populate our models with good quality data.

On our blog, there is a series of articles about Data-Driven Design and using a database during the design process. This is a useful process, though I realized that numerous projects are not yet ready to implement! The reason is bad data quality or no routines for data entry and management!

I decided to take a step back and start from scratch with an education process about data. Therefore, I want to kick off from the very basic level and dwell on data management on construction projects. In this entry, I will cover some definitions and theory (with practical examples as we use to do!) and then I will write about data entry, quality, management and more.

Table of Contents

What is data?

Let us begin with something absolutely basic and consequently, we will proceed with the difficulty level. So – what is data?

According to Wikipedia definition:
Data are individual facts, statistics, or items of information, often numeric. In a more technical sense, data are a set of values of qualitative or quantitative variables about one or more persons or objects.

Data gives us information about objects or persons and it can be transmitted or processed. A single value (datum) is often called a data point. Data is everything we create on our projects – from meeting recordings to complicated models. Some examples of data in our projects:

  • a pdf file (e.g. Product Data Sheet),
  • an e-mail sent to a coworker
  • a photograph of a construction site.
  • a fire-rating of a wall in our model.

Let’s move to something less obvious now.

Structured and Unstructured data

Data we produce can be structured or unstructured. It depends on how it looks and how we create it. I touched on this subject here. Let’s start with defining the difference between them.

Structured data (or data model) organises data points and defines the relations between one another. As the name suggests, it has to have a structure before placing it in data storage (such as relational databases).

BIM objects are a great example: a data model representing a wall is composed of other elements that define a wall: thickness, length, fire-rating, material, etc. To create a wall you have to put data into a predefined schema (each data point into a corresponding data field). Hence, structured data is also called schema-on-write. The most important feature of structured data is its query simplicity. Nonetheless, it requires an effort to create a set of data in a database.

Unstructured data is frankly speaking anything else. Unstructured information does not have a pre-defined data model. It is stored in a native file format. Accordingly, unstructured data are e-mails, pictures, pdf documents, meetings notes, etc. The biggest advantage of unstructured data is its simplicity to create and store. Yet to query it, a user has to understand how the format translates into pure information. Thus it is also called schema-on-read. A picture of a construction site has no data model and only a person accustomed to a subject matter can translate it into data, such as the number of floors, used materials, size of the construction, type of the bearing elements, etc.

This table shows examples of data we encounter on construction projects:

Structured Data Unstructured Data
Schedules E-mails
Bills of quantities Photographies
BIM objects Meeting recordings
BIM models Meeting notes
Excel spreadsheets (depending on quality) Excel spreadsheets (depending on quality)
Tender documents

What are properties?

We already know what is the data that we have in our projects. From now on, I will focus only on one type of project data: BIM models and what we have within. In fact, BIM is about objects’ properties. What are those then? This is a bit philosophical and surprisingly deep subject, but let us keep it stupid simple.

Property is a physical or abstract characteristic of an object. Physical properties indicate what this object is in the physical world: its colour, thickness, length or material it is made of. Abstract properties could be for instance: cost, object’s code (according to Uniclass for instance) or Control Area code.

What kind of properties do we have in our projects? To answer that question, let us leap back. As far as our first entry on this blog. As I described there, we divide BIM data into graphical and non-graphical.

Graphical data

Graphical data is all we see on the screen. Those are unstructured data and are used mostly to distinguish what different lines or surfaces mean. This type of graphical data are:

  • Line thickness
  • Line type (solid, dashed, dotted)
  • Colour
  • Annotation
  • Layer
  • Shape of the model
  • Characters and symbols
Graphical BIM Data
Graphical data in the model of New Stavanger University Hospital (Nye SUS), building 71.

Non-graphical data

Non-graphical data is all the information that sits within the drawings or models. This can be different schedules, areas of the room or volume. Those are physical properties that derive directly from the graphical design. If we think of 3D design as being a blunt combination of surfaces, it’s precisely where its properties are.

BIM models offer more of such data variety. As a result of separating building elements from plain 3D shapes and dividing them into classes (or categories), we can assign different properties to different elements. Each category has numerous properties, both physical and abstract.

User-defined properties

All BIM authoring tools, as well as IFC, comes with a variety of predefined properties. They can define the material, quantities, fire resistance, bearing elements and much more. Though projects often need additional properties to address specific requirements. This could be a definition of an object’s responsibility, its placing in the building or the maturity of the object. BIM technology gives us the possibility to create and define any data we want. We call them user-defined properties. I reckon this feature as one of the greatest power of BIM models.
User defined properties
Default and user-defined properties and property sets in popular IFC viewer - Solibri.

Property sets

Each BIM object has hundreds of properties. To have them all listed one after another would be extremely cluttered. Therefore we use property sets – a grouping of properties. IFC schema has its grouping, each BIM authoring tool has its own. You could think of them as chapters in a book or sheets in an Excel spreadsheet.

Predefined property sets are grouped logically. In IFC viewer you will commonly see property sets: Identification, Location, Relations or Quantities.

User-defined property sets group together user-defined properties. Such grouping should be described in BEP (BIM Execution Plan) and I recommend sticking to some rules for grouping them. Otherwise, users might always misclick or misspell this set (been there).

Properties and property sets in Solibri
Properties and property sets of a door on Nye SUS project.

What is a BIM model?

To conclude this theory introduction, let’s now join all these parts together and describe what is a BIM model. Datawise.

First of all, a BIM model is what we see on the screen: a 3D model, which presents unstructured graphical data (schema-on-read to understand what is shown on the screen). But in the background, a BIM model is nothing else but a database: non-graphical, structured data with both physical and abstract properties of the objects. Each object is a table and each property is a column. Objects relate to one another in the same way a relational database creates connections.

Take a look at the infographics below to get an understanding of how the data sets relate to one another.

DATA in BIM infographics
Subsets of data and BIM objects - inforgraphics.

Why do we need properties?

You should know by now what is data, what are properties, what kind of properties we have in the projects and how we group them. Before we wrap up, I want to address the last question: what are we using those properties for? There are several reasons why we need properties on projects.

To have all information available in one place.

This one is repeated constantly while talking about BIM. But this is indeed helpful. As a result of the connection of graphical design with non-graphical information, we are able to edit data on the flow and ensure better data quality. Though this might not be perfect as of now. BIM design has still a long way to go, especially regarding available data types (I will elaborate on that subject in the following article).

Scheduling and Quantity surveying.

Areas and quantities are always just a part of the quantity surveying process. The other part is to grasp the building data, technology and construction process. Since the design, quantities and other properties are now interconnected, quantity surveying has become a considerably less tedious drudgery.
Schedules in Revit
Door schedule on Nye SUS project.

Filtering

Here comes the real power of properties. In chapter 2 I stated that structured data’s biggest advantage is the simplicity of querying and filtering. BIM models give the possibility of easy filtering and sorting of received information. With filtering, queries like “Show me all objects that I am responsible for designing. Show me all objects that are still in the early design phase.” can be easily addressed.

Filtering in Solibri
A query of a Control Area (half of the floor) on the Nye SUS project.

Exporting data to Business Intelligence software.

Since BIM is a database and properties are columns, it means that we can easily reuse our design in various types of software. We are not forced to cooperate only through a model. We can for instance focus only on data and send our BIM database to software such as Power BI (if you are keen on learning how to do it, let me know in the comments and I can create a tutorial!). And this opens a whole new world for the data analysis of our projects.

Facility Management and unique coding

Increasingly more BIM projects consider reusing the model in the FM phase. One of the solutions to make it work is to give every object a unique code that would exist both digitally and on the physical object. In the BIM model, the solution is to create a corresponding user-defined property, which will be used on-site after the project is finished. This enables Facility Managers to easily identify the object in the model and find the correct equipment in a technical room.

Summary

In this entry I’ve covered a good chunk of theory, but I did my best to visualise practical examples from our AEC branch. Let me know if you’ve grasped the topic or need more clarifications! In the next article, we will dive deeper into the subject of data types and how to keep our datasets clean and useful. The more projects I see, the more I’m convinced that the ability to provide a model with good quality data is essential.

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Ibrahim
Ibrahim
22 days ago

Good Job !

BenoitLoze
BenoitLoze
22 days ago

Hi,

Nice!

More than interested in Power Bi Tutorial.

Thank you,

Best Regards,

Benoit

Pille-Riin
Pille-Riin
9 days ago

Great article!

I’m also interested in learning how data from BIM models can be used to enhance project management or how it can be used overall using PowerBI.

Pheinue
Pheinue
7 days ago

I am studying the combination of BIM data and graph database. Do you have a similar case?

Pheinue
Pheinue
7 days ago
Reply to  Konrad Fugas

I think BIM data can be divided into geometric data, topological relationship and engineering data. Among them, topological relationship is the most important data of BIM data. In order to share more conveniently, I need to convert these data into a database. At present, graph database is one of the best choices. We have developed a software to import all BIM data into this software for data management and sharing.

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