buildingSMART Forums

Logistic, phases and time in ifc definitions

Hi,
I was wondering if there are properties in the ifc file schema that can be used for logistic and phasing purposes (aka 4d bim). If you want your bim data to be used in a Building Smart environment the aspect ‘time’ is crucial for good visualization and scheduling. There is a wide variety of socalled ‘4d bim software’ available to !CONNECT! geometry databases to some sort of excel or other planning database. I cannot find documentation that this 4d aspect can be incorporated in as ifc definition to begin with. Any examples of doing 4d with ifc.

I think some variables in the form of ifctimeerected or ifctimemounted would be crucial for builders and would make it very a software independent and useful.

As fas as i can oversee the practice of today is that sadly a lot of ifc is exported and imported according to the phase. This the risk of having too many (offline) duplicate clumsy exports to maintain in folders somewhere. Not mentioning the file hussle and waist of time importing exporting communicating. Needs to stop.
Thanks

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Hi Hans,

It’s really hard for me to understand your view, but it seems that you’re talking about:

  • “dynamic” data/information exchange
  • and data/information management in an efficient way, when it doesn’t need teams send and receive “duplicate” data/information,
  • and also “time-series”

Is there something more? Also you talk about which IFC schema version? IFC2x3 or further?

Yes, dynamic and interactive data are the words to describe it. ‘4d bim’ what’s being sold now is a link between two databases. Geometry on one side, timeline the other side.

Is the ability to work 4d based on ifc a subject still under research or is this an aspect part of the cerfification? Or, …what else?

“Researchers have studied the detection of actual site conditions and the state of construction progress using various field data capture technologies. To fully exploit these solutions, a method was developed to automatically update industry foundation classes (IFC) based four-dimensional (4D) building information models (BIM) in terms of schedule and progress. To automatically incorporate progress data into 4D BIMs, the method modifies the schedule hierarchy; updates progress ratios for the building elements; color codes the building elements based on their actual and expected progress; and updates the task durations and finish dates…”

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In 4D, the methodology is really important, and it seems that the research you mention was/is good enough when compares as-design and as-built and automatically updates schedules

@Hans_Lammerts

At first, I thought you could use https://standards.buildingsmart.org/IFC/RELEASE/IFC4_1/FINAL/HTML/link/pset_constructionresource.htm

But I think it would be better to use https://standards.buildingsmart.org/IFC/RELEASE/IFC4_1/FINAL/HTML/link/ifcresourcetime.htm

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GeometryGym has implemented the 4D BIM IFC entities.

The BlenderBIM Add-on has not publicly implemented it, but I have personally generated 4D BIM data from it, and created animations from the IFC. It’s on the to-do list to make it a publicly available feature.

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Dion, as always you do a great job

However, I’m still not sure what Hans wants or mentioned. He shared a picture that shows an approach which is a step further than CPM, but based on the methods you use in 4D and 5D, the data/information and processes would be different, and you have to use some other time Entities or Psets than IfcResourceTime and Pset_ConstructionResource

4D and 5D is an ocean, however, the most recent methods in the industry are based on “Toyota Production system’s continuous improvement spiral” which I preferred to illustrate it as a loop

4D

(but I don’t see some signs needed to say that solution uses the emerging method or methods)

Different software for different purposes. Ifc as schema to unite them and share data. A tool like Navisworks, Synchro, you name them. They should be able to import ifc. After the timeline is set, exporet it with included building time planned as a ‘4d bim file’. (The most common perception of "4d’ is 3d plus time, no oceans here) So a ifc file that describes objects AND the planned data for building. This ifc can then be used in the next (visualisation) software.

It’s not that hard to imagine, is it? So this is being developed. Great! Good going Dion!

@Hans_Lammerts - yes, since IFC4 there is the capability in the IFC schema to associate a task to a product - which is the result of 4D scheduling, with different possibilities to assign time to a task, and to group tasks in schedules (and have calenders for schedules).

See this small example: https://standards.buildingsmart.org/IFC/RELEASE/IFC4/ADD2_TC1/HTML/link/construction-scheduling-task.htm

Attached is also an old article that explains the concepts behind (plus associating construction costs to tasks, which goes even further).

20090421_Model-basedScheduling_DiscussionPaper.pdf (1.8 MB)

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I like this:

Because I work on Lean Construction and some other methods that need some other new times but can handle them with some classes/objects like IfcTimePeriod

In the near future will come back to you to explain them all

Also, it seems that in the industry and academia there’re some different names. Personally I like these names:

  1. Explicit
  2. Derived
  3. Inverse

The image you shared is the D-studio SketchUp plug-in, which links activities from project planning to Sketchup components. That version was not aligned with IFC.

http://www.4dvirtualbuilder.com/

Yes. I know. Would be great to have it ifc timelimed compatible too.

There’re few countable platforms in 4D/5D, especially platforms that can automatically generate tasks from IFC file

And most importantly, use new methods, not old-fashioned ones like CPM

For instance, Lead Time (LT) is one of the important times:
https://www.designingbuildings.co.uk/wiki/Lead_times_for_construction