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BBIM | Formworks in IFC, anyone?

  1. S by steverugi on 12 May 2024, edited 27 May 2024 # +4 votes

    Looking for the right way to classify formworks, I found a predefined entry under IfcConstructionProductResourceType

    So I thought " OK, maybe I model them using IfcCovering and check if it can work with resources> BoQ in a Cost item for Concrete.."

    then I found out that Product is somehow treated differently in the Resource panel:

    Question:

    In general, what is the right way to work with formworks in IFC?

    using IfcCovering I can get their area quantity but I was wondering if there is a more appropriate procedure, especially when the Cost Item's quantity is derived from Resources, like in a rate build-up.

    thanks in advance for your help

    Edit

    going through IFC docs I realized that unlike

    • Qto_ConstructionEquipmentResourceBaseQuantities

    • Qto_LaborResourceBaseQuantities

    • Qto_ConstructionMaterialResourceBaseQuantities

    there is no provision for Product.. because it defines a "role"?

    so my best guess atm is to identify formworks using Material and set it as WOOD and be happy with that :p

  2. A by Arv on 15 May 2024 #

    Hi @steverugi ,

    This is quite an interesting area of work. I had checked on working with formwork earlier, but couldnt pursue it further then.

    This is what I've understood about IfcConstructionProductResource from IFC documentation

    • unlike IfcProduct, there's no IfcProductRepresentation for IfcResource. So I'm not sure whether you'll be able to 'show' them in 3D

    • They do have an attribute that is BaseQuantities which could be area, volume, length, weight, but I guess these are to be entered as value unlike calculating them from the shape product (Maybe the values from calculating the Surface area from shape representation can be processed here)

    I'd happy to explore more on these here :)

  3. S by steverugi on 15 May 2024 #

    Hi @Arv :

    This is what I've understood about IfcConstructionProductResource from IFC documentation

    • unlike IfcProduct, there's no IfcProductRepresentation for IfcResource. So I'm not sure whether you'll be able to 'show' them in 3D
    • They do have an attribute that is BaseQuantities which could be area, volume, length, weight, but I guess these are to be entered as value unlike calculating them from the shape product (Maybe the values from calculating the Surface area from shape representation can be processed here)

    thanks for your input, please where did you find the BaseQuantities related to an IfcConstructionProductResource ? I couldn't find any Qto_

    cheers

  4. A by Arv on 15 May 2024, edited 15 May 2024 #

    Its a direct attribute available under IfcConstructionResource and not as a property

    check the documentation link

    I wonder if there are any ways to show any representation though. @steverugi how have you been able to bring in shape representation here

  5. S by steverugi on 15 May 2024, edited 15 May 2024 #

    @Arv said:

    Its a direct attribute available under IfcConstructionResource and not as a property

    OK

    check the documentation [link]

    I wonder if there are any ways to show any representation though.

    me too, I think the BaseQuantity here is for consumption , not quantity related to an entity, maybe more a 4D thing?

    @steverugi how have you been able to bring in shape representation here

    I wasn't, what I showed in my first post was from the Resources panel, it's a bit of uncharted territory for me here, sorry

    I mean, I am very familiar with resources used in a program of work (MS Project) but I haven't got the chance yet to fully implement it in an IFC/BBim scenario

  6. W by walpa on 20 May 2024 # +1 votes

    @steverugi This is an interesting topic and some light needs to be shed on it.

    In my understanding:

    An alternative: formworks should be classified as an IfcBuildingElementProxy element and assigned to IfcConstructionProductResource through an IfcRelAssignsToResource relationship.

    As per "A resource may have assignments of other objects using IfcRelAssignsToResource where RelatingResource refers to the IfcConstructionResource and RelatedObjects refers to one or more objects such as IfcActor or IfcProduct subtypes. This relationship indicates specific objects assigned to fulfill resource usage." here, and the excellent "cost_time_resources_management_rev002.svg" diagram that SigmaDimensions created and made available in May 2021 in this discussion.

    I think this direct assignment was not implemented in the BB interface.

    Another alternative: assign the element as input to a task in the Task ICOM panel

    But it is necessary to deepen the understanding of how the BaseQuantity would be calculated in IfcConstructionProductResource, through the assignment in the task, I don't know if this was also implemented.

    Good question to @SigmaDimensions guide us.

  7. S by steverugi on 21 May 2024, edited 21 May 2024 #

    Hi @walpa

    thanks for your reply

    In my understanding:

    An alternative: formworks should be classified as an IfcBuildingElementProxy element and assigned to IfcConstructionProductResource through an [IfcRelAssignsToResource] relationship.

    is this a proposal or something implementable in BBIM's UI already?

    Another alternative: assign the element as input to a task in the Task ICOM panel

    yes, of course, but I think it doesn't address the ProductResource issue

    But it is necessary to deepen the understanding of how the BaseQuantity would be calculated in IfcConstructionProductResource, through the assignment in the task, I don't know if this was also implemented.

    sure

    PS the 1st link is broken but the one to the .svg document was very useful thanks

  8. A by Andrej730 on 23 May 2024 # +1 votes

    @walpa said:

    I think this direct assignment was not implemented in the BB interface.

    I think it is implemented. Though I'm not sure if this relationship is actually used somewhere.

  9. W by walpa on 24 May 2024 #

    @steverugi said:

    PS the 1st link is broken but the one to the .svg document was very useful thanks

    Sorry, correct link: IfcRelAssignsToResource

    @Andrej730 said:

    I think it is implemented.

    yes, thanks, it is implemented

    By this way, I think the quantity should be assigned manually (this seems to be what the documentation indicates)

    BB accepted IfcQuantityArea for IfcConstructionProductResource, a little different from what the documentation indicates. IMO BB is correct.

    But for IfcQuantityCount it gave an error.

    I will go through the task ICOM and if I have any success I will return here.

    Cheers

  10. A by Andrej730 on 24 May 2024 #

    @walpa

    BB accepted IfcQuantityArea for IfcConstructionProductResource, a little different from what the documentation indicates. IMO BB is correct.

    Looks like a bug though if documentation explicitly says that IfcConstructionProductResource can only be IfcQuantityCount.

    But for IfcQuantityCount it gave an error.

    I don't have this error. Can you please test with the latest BBIM build and if error persists share the .ifc file to reproduce this?

  11. A by Andrej730 on 27 May 2024 # +2 votes

    @Andrej730 said:

    BB accepted IfcQuantityArea for IfcConstructionProductResource, a little different from what the documentation indicates. IMO BB is correct.

    Looks like a bug though if documentation explicitly says that IfcConstructionProductResource can only be IfcQuantityCount.

    Implemented in this commit.

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