I like what I see in “Advanced (Level 3)” and for sure the industry is following this when bSI is thinking to develop OpenCDE which is API-based
However, I think bSI is improving IFC to be suitable for ISO 19650 which CDE is an important part of it
But till now I haven’t seen any evidence about IfcOwnerHistory improvement inside the IFC schema
CDE at the end needs support IFC and ISO 19650
Even maybe there would be a need to improve “time-series” too, I’m not sure yet
Could you please explain what you mean with "… haven’t seen any deviance about IfcOwnerHistory improvement … " ?
Thanks, I mean evidence
In IDM Tookit project I saw a lot of good improvements which I think are good for the start and during the time bSI can improve it
But I don’t know is it an open source project or not? It would be part of IfcDoc or OpenCDE or not?
First, as an owner a change log is definitely of interest. But from my perspective, it is the responsibility of the building owner to keep his own change log. For this purpose, the last change coming with an IFC file is sufficient to log into the owners system. That way, the owner can easily maintain the changes important to him in his own system.
That being said, I care about my exchanges, so I would prefer not to get the entire log of changes in models into my system. Only the ones I care about. The changes I care about are in the specific exchange that I have specified in scenarios where I get data from designers, contractors etc.
I have something in mind that needs all change logs
But yes, we can implement these change logs out of IFC and just share the start and the last log
Imagine you design and after a while you realize that you did wrong and your client wanted you did it in another way. What you do? You have to start from where? Start point? What if you be able to come back to the point that you want and start from that point?
It will reduce times and costs when you have the ability to come back in change logs or go ahead
“Imagine you design and after a while you realize that you did wrong and your client wanted you did it in another way.”
It is fairly common, facing the outcome of formal written demands and finally seeing the result as 3d model. The visual model or even drawing is a form of communication. ‘Seeing it with other eyes’ from an other perspective…
Good thing it happens. No accident happend. Good. Only then it will start a new ‘deeper thinking’ proces. Let the ping pong proces of making things better begin 
I would consider change log for administration purposes. Like putting up the bill of manhours or gibr management an overvoew. BUT NOT for making the design better or definite.
Going on my own experiences as a designer i will say that change logs are not the first thing people would use for chaning things back. It not a logical way. Eventhing is in their heads anyway.
And…‘There is NOT one bim-model’ so neither is there 'one bimmable ifc file" (which is perfectly in line with the writing of leon van berlo once wrote for bsi) And neither is the 1 moment for changing of thoughts with your client.
What i am trying to say is that probably one (done right:1) step will be gone back in the proces and the model adjustments will simple be ‘undone’ and changed. Design teams will be prepared for this to happen. Commen practice. No difficult CDE changelogfilecoldcasestudy required really. Not saying change logs certainly have a important function. But not in favor of completing a model in the right way (right being: this is how my client whises!)
For the design proces a change log would not be be part of the ifc. It will make 3d modelling unnecessary complex. And personally i find it not logical to put it in any form of 3d model. Not during operation phase either.
Theory versus pratice. (?)
I think 2-3 people know what am I want and what am I going to build which is not as same as what’s happening in the projects today
If I spend my time in something, I want it be more advanced than what’s “general” in the industry
I tried give a simple example to show a small part of a “Design System” that is not following a linear process and has a more flexibility as well as “accurate” aspect
When you provide just “start” point and “end” point, and drop between, it means that you drop some data/information that “maybe” be useful or useless and who knows we should drop them or not?
I mean when IfcOwnerHistory just provides start and end maybe cause “DATA/INFORMATION LOSS”
I don’t prefer minimum and also maximum, instead I prefer just enough data/information and knowledge
Ok. Good luck
I would consider change log for administration purposes. Like putting up the bill of manhours or gibr management an overvoew. BUT NOT for making the design better or definite.
@Hans_Lammerts You mentioned change log for administration purposes, so let’s accept this which is true.
So, do you think IfcOwnerHistory would be better to improve or not?
Also, I mentioned maybe in short term it causes complexity and increases in file size, but in the near future when bSI or some individuals implemented “federated” IFC, it won’t increase file size because you can divide an ifc file to many small but integrated parts. Fore instance, some ifc files that just hold change logs, some hold materials, some hold products, some hold projects, some hold sites, …
So, it seems that all of us agree about improving IfcOwnerHistory but see it with different views, for instance @sergej wants protect his change logs and share just preferred ones which is good
And I have the same view too, but see a CDE as an “integrated distributed system(s)” which is what we see in new generation of platforms and is one step ahead of ISO 19650
I don’t think this handle works properly in software. I personally do not like the idea of logging changes inside ifc
Ditch it.
The way people work with bcf files and manage these as changes would probably be a better starting point
OK 
Personally don’t see BCF as an efficient way.
But I should show you what’s efficient, then all of us have to wait
Some years ago Arup developed BCF 2.0 and after a while some from Solibri and other companies with a little bit change released that as BCF 2.0 and today BCF 2.1
It’s odd to me when we talk about BIM Level 3 but still minds have focused on BIM Level 2
It’s odd to me when today we talk about Industry 4.0 when it seems that some even didn’t experience Industry 3.0
Personally I’m happy I’m in the built environment industry, because the industry’s weakness opens a lot of opportunities
Where i can i personally try to avoid any of these abbreviations. It creates many confusion.
Bim
Level x
Industry x
These abbreviations don’t cause confusion
The majority of them and their goals are clear, but do you know, “change is painful, so normally many try to avoid”
However, all big changes has happened through small groups who knew what they wanted and weren’t following norms
I won’t follow technologies and methodologies that are based on 30-10 years ago
What “norm” is it that you don’t follow, and i do?
I don’t talk about you Hans, please don’t see this personal
I just say we need new methodologies and technologies, and IFC improvements
And I think I shared enough about everything
About SysML/UML about Modelica and what am I want today? Which I think some bSI friends realized
There’s almost 3-4 years I follow “System of Systems” goal and I think today technology gives us enough power to build platforms that support many things that were separated before
It’s the time for combine, not integrate, GIS, BIM (BLM), PLM, …
So, IFC “can” be the main choice if has improvements and be update
Nothing personal. Just trying to understand your plans and struggles with ifc
We’ve focused on:
Also, like VFX industry and its software I want IfcOwnerHistory supports all logs that end user be able to has a full control on her/his design and implementation efforts. Be able to come back to the nodes she/he wants and changes them easily. Like what we see in video/cinematic production
Sounds like we’re on different paths indeed
I don’t know what’s your path, but if it’s AI-based, should say that today AI is a general “material” in every solution
But AI is a general word, the solution and the method matter most