Can you check my COBie? Part 1: To IFC, or not to IFC, that is the question
First of all – I am a big advocate for the use of COBie on construction projects (even if it’s not required by the client). Secondly, the question we’re asking is wrong! Let me explain why.
Intro:
There are many articles written about COBie and I don’t want to dwell on it too much, so in a nutshell, I’ll point out a few key drivers for including it on the projects:
- It’s a common exchange format (interoperable)
- It includes a lot of information about maintainable assets and the facility itself
- It is structured and machine-readable (and testable)
- And it is quite often a contractual deliverable.
When COBie is included on the project there is always this nagging question:
To IFC or not to IFC?
First things first – Industry Foundation Classes (IFC) is a schema and not a file format, there is no such thing as an IFC file. COBie is a subset of IFC. Now somewhere along the way, the industry decided that the STEP Physical File format (often incorrectly referred to as just IFC) is the answer to all problems, but it’s not as simple as that.
Let’s get technical for a bit (this is going to feel like a rabbit hole, so refer to the image below). ISO16739 is a standard for IFC. This standard defines something very important – logical data structure (schema). Files conforming to this schema must be formatted and delivered utilising ISO 10303 Standard for the Exchange of Product model data (STEP). STEP has many parts [1]. One of those parts (ISO 10303 Part 21) is well known – STEP Physical File Format (SPFF). It is normally used to exchange design information. The other one, ISO 10303 Part 28, defines the XML format to exchange IFC data. There are many file formats used to exchange IFC data. ISO16739 defines these alternative file formats and this is where the COBie Spreadsheet Physical File Format comes in!
The other very important part of the IFC standard is Model View Definitions (MVD). As you can imagine the IFC schema is like a dictionary describing every possible object found in the built environment. There is no discipline in the world that would require all this information all at once. Therefore, Model View Definitions take a portion of the IFC data and use it to exchange information from one system to the other. Some of those definitions overlap in the data that they exchange, but they all serve a specific purpose. An image below shows this relationship:
As you have probably guessed it – COBie is defined as an IFC MVD. This means that it can be delivered using different file formats. The most popular is the COBie Spreadsheet Physical File Format.
While theory states that COBie may be delivered using different file formats the industry tried to force the use of SPFF. However, many professionals ran into a little problem.
- The majority of software providers did not implement COBie in the SPFF format. Instead, they implemented COBie in a spreadsheet format.
This drove the industry mad since BIM consultants required COBie in SPFF, but not all design software could produce compliant COBie in SPFF.
In fact, Revit, like many other software providers, implemented COBie in a spreadsheet format and it absolutely made sense, since the majority of Computer Aided Facility Management (CAFM) software providers did exactly the same. Thus, pushing the information from Revit into SPFF would result in an extra conversion (SPFF to spreadsheet) in order to push the information to the CAFM.
OK, let’s now look at the software that is used by construction professionals that are not in the office and are not spinning the model all day long. People who actually select, submit, evaluate and procure manufacturer products, are office engineering and procurement staff, who use systems designed for ordering and tracking equipment delivery [1]. These people do not rely on the graphical representation of the model, they normally use schedules and various forms to complete their tasks. While linking data to the models would provide an interesting interface to view your project information, the data required to run a facility is not geometrical at all. What is needed is the manufacturer’s maintenance plans, warranty information, barcodes and serial numbers.
As you can imagine these people will not likely use software that supports the specialised file format SPFF and it is likely that the good old spreadsheet will be utilised to exchange the information. In simple terms, you can open it in any spreadsheet application.
Wait for a second, you may ask – you must have heard of the scenarios where all this data is being captured in the model using Revit! But take a moment to think about what it would take to capture installation dates or serial numbers in Revit.
So where does the SPFF fit in?
I think at some point BIM consultants thought that they are too cool for COBie school and spreadsheets are too simple for the construction industry. Additionally, there is nothing sexy about the spreadsheet. Simply put – you cannot spin the model around in front of the client and say ‘look at all this data’.
Furthermore, there is another, more sinister reason (don’t judge me too harshly – I work as a BIM consultant myself). Let’s imagine that you are a BIM consultancy and you have Solibri Model Checker as the primary software to check COBie. It makes sense to ask the project team to deliver COBie in SPFF simply because you are probably the only member in that team with software capable of checking incoming models!
It makes sense to ask the project team to deliver COBie in SPFF simply because you are probably the only member in that team with software capable of checking incoming models!
Additionally, most of the consultants will not be able to deliver COBie in SPFF because even the software providers do not implement COBie in SPFF. Also, it is time-consuming and relatively complex to push data back into the models for no apparent reason at the construction stage, especially when everybody knows that this data will find its way back to the spreadsheet anyway. However, if you’re a BIM consultancy this scenario is good for business as you will be providing valuable reports and supporting the team by assisting them with technical queries on how to export the SPFF in the ‘correct’ way so you can charge the client for all this time.
But did you know that there is a free COBie QC Reporter on Github? You shouldn’t be surprised to know that it checks COBie data in a spreadsheet format. However, if you tried to use it, you would see why the industry wasn’t grabbing the solution of the shelves. First of all, you literally need a guide to even install it. Secondly, you need another guide to run it. Thirdly, customising it to meet client requirements is a task on its own. Lastly, the report presentation is not very easy on the eye or straight forward:
Let’s not blame BIM consultancies for taking the opportunity to provide a solution to their clients though, I just wish COBie wasn’t implemented through the introduction of SPFF into the process as it added unnecessary complexity to the entire COBie delivery and checking process.
So, to answer the question of whether to IFC or not to IFC, I would say not to SPFF. At least not until SPFF is tested and implemented by the software providers. For now, stick to the good old spreadsheet format (which is based on IFC, if you still feel a bit confused).
P.S. If you want to learn more about upcoming Model View Definitions go ahead and Google “FM Handover – Equipment Maintenance MVD”.
P.P.S. the article above represents my personal views only.
References:
[1] Introduction to COBie: Foundation Knowledge; E.William East, Shawn O’Keeffe, and John Ford