PLQ2.5 – To GUID or not GUID?

Hello BIMfans,
After last week’s post COBie Round 2 where I managed to solve many of my outstanding COBie issues, I was planning to provide an informative post about asset management as I was having my gutters replaced; sadly plans changed. *sigh*

Despite giving a very detailed explanation and approving an itemised quotation, my builders showed up with no clue of what work needed doing and once they were briefed and checked the stockists told me that they needed to pre-order the materials after they arrived on site to install (Don’t worry, they will be getting terrible review on Rated People!).

Two key points that resonate out of this omnishambles:

  1. The best laid plans of mice and men often go awry.  Documents aside, how can I ensure that they can be turned into actions?
  2. I need a gutterer. If anyone knows someone who can come and fit new fascia, & gutter to my home; please let me know (Please!).

What is an Asset Identifier?

The work I was having done to my gutters got me thinking about Asset Identifiers and their use.  When I defined my Data Requirements I noted that I need to have a unique identifier for each of my assets so that each one has a unique reference to be registered, one of my Model Purposes.

Good management (and good graphics) need good data.

According to the BRE BIM Terminology Tool, a Unique Identifier is:

Role of a character string when used for unambiguous reference to a concept or to an individual thing (e.g. a physical object or an aspect or a fact or a relation type) and that is unique within a particular common context, preferably in a universal context

By applying a Unique identifier to my components, I will have their Asset Identifiers.  To save on effort, I initially thought it would be a great idea to use each component’s Globally Unique Identifier (GUID) as the asset identifiers.  To do so, I had set my HandoverMapping file to populate the AssetIdentifier field with their respective GUIDs.

Doing this is a stupid idea.

While it might seem logical at first as it does provide a unique identifier for each asset, I can’t control the GUID generated.  For example, shown below is the same door created in two difference instances of my house model.  Each was placed in the same location, when created each door and was given the same mark, but different GUIDs,

Not only are both GUIDs different, but I can’t change them.

Because I can’t change an object’s GUID it means that if I wanted to recreate my house model it would be impossible to match the same GUIDs, making them pointless as Asset Identifiers.  So I will instead be using numbers I can generate on‘s string generator.


What Triggers an Asset Identifier Change?

Now having an Asset Identifier is one thing, managing it is quite another.  If the builders had actually done what I expected, I would have new gutters; should these new gutters get a new Asset Identifiers?  To get an idea I asked Twitter:


As you can see, the majority of voters opted for a new identifier (and I agree) but it depends on the situation, as it is not manageable to do this every time an asset is modified. Therefore, I need is to define what operational actions are considered to be ‘trigger-related events’.

According to the BRE BIM Terminology Tool, a Trigger Related-event is:

Response to a trigger and the reflection of the altered state of the asset in the AIM

Information around triggers and trigger-related events can be found within PAS1192-3.  In particular, Annex A.5 provides a schedule of triggers which includes asset replacement. So I have decided to instigate what I am calling the ‘Sticker rule’.


Imagine that every component in my home has an asset tag sticker.  Any trigger that involves replacing a component will need a new sticker, because the current one is stuck to the old component (on its way to the tip); a new sticker means a new asset identifier.

So to capture this I have modified my Employer’s Information Requirements to include the following clause:

When managing the information model during operation, asset information shall be updated following the schedules trigger-related events below:

  • Receipt of information following minor works;
  • Receipt of information following major works;
  • Performance evaluation of an asset;
  • Condition evaluation of an asset;
  • Maintenance work on an asset, whether planned or reactive;
  • Asset replacement; and
  • Change in maintainer of an asset.

Where a trigger-related event has resulted in the replacement of any assets, those assets shall be given new Asset Identifiers.

Who knows, maybe when I eventually find someone to do some work on my home, I might be able to put this into practice!

And there we have it, by thinking about how I am going to use my asset information I have started to establish a simple and pragmatic trigger event strategy to control how and when I update my Asset Information Model.  All good information to help complete PLQ2.5!

Model Generation:
2.1 What existing information is available?
2.2 Is there sufficient information to produce a BEP?
2.3 What is the layout of the house?
2.4 What assets are contained within?
2.5 What asset information can be linked to the graphical model?

Now that I have a system in-place, I need to do some data entry into my model…

4 thoughts on “PLQ2.5 – To GUID or not GUID?

  1. This new technology seems a bit like carting coal to New Castle by wheel barrow
    when you could buy a bag in a local corner shop


    • Hi Sheila, yes if people are not careful it can quickly spiral out of control. That’s why only what is needed should be included (see an early post about my model purposes). If the data isn’t vital day to day, then often it will be easier to collect at the time required instead of taken up resources to maintain it.


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