What is the power of IDS for the correct operation of IFC data?

A "Beast of Possibilities = IDS" that not only standardizes attribute information and how to exchange information with customers, but also can clearly standardize LOD+LOI and LoIN in BIM.

Sep 15, 2023

What is IDS？

Have you heard of IDS?
IDS is a concept first described in the 2020 buildingSMART technical roadmap and stands for Information Delivery Specifications.
We feel that it came to the forefront in earnest at the bSI Rome Summit in March 2023, and its details are currently under development.
IDS is a file in XML format that defines what kind of information and what kind of model structure is required by the ordering party for the ordering party and at what level (degree) in the IFC data.
Basically, it is operated together with the IFC data.

For example, the IFC data description and structural specifications required by the client must be described for each IFC entity, for example, there must be no fire resistance properties for the walls included in the IFC data, the material property of the wall must say concrete, and this entity must be included below this IFC entity, etc. entity, such as "the wall material property must say concrete," or "include this entity below this IFC entity.

The conventional digital description standard approach for describing the information required by the client is Excel or PDF (and in different formats), etc. With the advent of IDS, the performance required by the client for IFC data can be easily read by a machine.
Below is an introduction page to IDS by buildingSMART.
https://www.buildingsmart.org/what-is-information-delivery-specification-ids/

It is very relevant to ISO 19650's EIR (Exchange Information Requirements) and we believe it will be useful for mutual development with LOD+LOI and LOIN (Level of Information Need).

How to write IDS Preparation

I would like to say that it is very easy, but it is a bit complicated. First, here is the official documentation.
https://github.com/buildingSMART/IDS/tree/master/Documentation

And here is a sample file of IDS.
https://github.com/buildingSMART/IDS/blob/master/Documentation/library/sample.ids

STEP1　Describe metadata.

IDS is written in XML format, and as the basis for XML data, the first step is to describe the metadata, which is the basic information. Eight items are required.

title
copyright
version
author
date
description
purpose
milestone

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ids:ids xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://standards.buildingsmart.org/IDS http://standards.buildingsmart.org/IDS/ids_09.xsd" xmlns:ids="http://standards.buildingsmart.org/IDS">
  <ids:info>
    <ids:title>Trial Information Exchange Requirements</ids:title>
    <ids:copyright>ONESTRUCTION Inc.</ids:copyright>
    <ids:version>1.0</ids:version>
    <ids:description>Currently, information requirements for delivery data are defined as attribute information, but the means to check these requirements are currently conducted in a labor-intensive manner by human eyes and hands.
Therefore, this IDS is used to check whether the delivery data contains the information as per the quantity or whether the quantity is insufficient.</ids:description>
    <ids:author>y.miyauchi@onestruction.com</ids:author>
    <ids:date>2023-08-10</ids:date>
    <ids:purpose>Confirm that the information desired by the client is included in the delivered data.</ids:purpose>
    <ids:milestone>Design</ids:milestone>
  </ids:info>

STEP2　Define Specifications (information format).

Specifications (information forms) must contain two major items.
" Where it applies" and "What are the requirements?" In the official documentation, they are listed as Applicability and Requirements.

Example of how to write common parts.
Include the name of the specification, the IFC version, and an explanation or note of the information format.

  <ids:specifications>
    <ids:specification ifcVersion="IFC2X3" name="#1　attribute conditions on entities" minOccurs="1" maxOccurs="unbounded" identifier="01" description="Describe why this condition is necessary." instructions="For example, provide guidelines on how it is OK to be described.">
    </ids:specification>
  </ids:specifications>

Example of how to write Applicability parts.
The Applicability describes to which IFC entity the rule (condition) applies.
For the Predefined part, please refer to the official documentation of each entity.
https://standards.buildingsmart.org/MVD/RELEASE/IFC4/ADD2_TC1/RV1_2/HTML/

      <ids:applicability>
        <ids:entity>
          <ids:name>
            <ids:simpleValue>IFCBUILDING</ids:simpleValue>
          </ids:name>
        </ids:entity>
      </ids:applicability>

Example of how to write Requirements parts.
Specify the applicable conditions such as material, which pset should contain the required information, IFC structure rules, etc.

      <ids:requirements>
        <ids:attribute minOccurs="1" maxOccurs="1">
          <ids:name>
            <ids:simpleValue>Name</ids:simpleValue>
          </ids:name>
          <ids:value>
            <ids:simpleValue>Bridge</ids:simpleValue>
          </ids:value>
        </ids:attribute>
      </ids:requirements>

Facets are defined in various ways and can be written in the following six ways.

Entity Facet
Attribute Facet
Classification Facet
Property Facet
Material Facet
PartOf Facet

Completed IDS (sample)

<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ids:ids xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://standards.buildingsmart.org/IDS http://standards.buildingsmart.org/IDS/ids_09.xsd" xmlns:ids="http://standards.buildingsmart.org/IDS">
  <!--edited with usBIM.IDSeditor (http://www.accasoftware.com)-->
  <ids:info>
    <ids:title>Trial Information Exchange Requirements</ids:title>
    <ids:copyright>ONESTRUCTION Inc.</ids:copyright>
    <ids:version>1.0</ids:version>
    <ids:description>Currently, information requirements for delivery data are defined as attribute information, but the means to check these requirements are currently conducted in a labor-intensive manner by human eyes and hands.
Therefore, this IDS is used to check whether the delivery data contains the information as per the quantity or whether the quantity is insufficient.</ids:description>
    <ids:author>y.miyauchi@onestruction.com</ids:author>
    <ids:date>2023-08-10</ids:date>
    <ids:purpose>Confirm that the information desired by the client is included in the delivered data.</ids:purpose>
    <ids:milestone>Design</ids:milestone>
  </ids:info>
  <ids:specifications>
    <ids:specification ifcVersion="IFC2X3" name="#1　attribute conditions on entities" minOccurs="1" maxOccurs="unbounded" identifier="01" description="Describe why this condition is necessary." instructions="For example, provide guidelines on how it is OK to be described.">
      <ids:applicability>
        <ids:entity>
          <ids:name>
            <ids:simpleValue>IFCBUILDING</ids:simpleValue>
          </ids:name>
        </ids:entity>
      </ids:applicability>
      <ids:requirements>
        <ids:attribute minOccurs="1" maxOccurs="1">
          <ids:name>
            <ids:simpleValue>Name</ids:simpleValue>
          </ids:name>
          <ids:value>
            <ids:simpleValue>Bridge</ids:simpleValue>
          </ids:value>
        </ids:attribute>
      </ids:requirements>
    </ids:specification>
  </ids:specifications>
</ids:ids>

IDS out of scope or slightly misunderstood, need for prerequisite knowledge and rules

Listed as outside the scope of the IDS are, for example

Geometry check
Interference Check
Design requirement

However, if one is familiar with IFC, some of these barriers can be overcome with some ingenuity. For example, geometry checks and design requirements can be checked by IDS, depending on the information design and entity selection to be carried in the pset.

Before using IDS, one must have the skills to inventory the rules in the first place, but how to map them to IFC is impossible to build IDS without knowledge of IFC.
Projects using IDS will not be successful unless the organization and managers are able to draw a story of how IFC will be operated.

Of the six facets mentioned above, the PartOf facet helps users define the IFC structure. While knowledge of IFC is essential for operating facets, PartOf facets can only be constructed with in-depth knowledge of IFC and rules for how BIM data should be constructed.
On the other hand, making full use of PartOf facets can be a major factor in preventing IFC files from becoming stray and supporting a company's data usage infrastructure. It can also strengthen the linkage with LOD and LoIN, and contribute to stricter staircase design of geometry, since it allows for strict IFC structure rules.

Future of IDS

I believe that the promotion of openBIM will be accelerated if the client or its supporting consultants define IDS. For example, in the field of civil engineering, IFC data, which for many contractors used to exist only for delivery, will be able to be checked to see if the model meets the client's requirements, and LOD can be made stricter (standardized) by using facets, so that the contractor will be required to create correct IFC data. The IFC will require that the client create the correct IFC data. For companies, this will help prevent the generation of stray data within the company. （The use of IFC is expected to accelerate (of course, the rules of IFC structure need to be determined first).

Those who need help with IFC operations, rules and regulations, etc.

ONESTRUCTION, Inc. is staffed by IFC professionals with knowledge of how to manage and operate IFCs within projects and companies, and how to use them as fundamental information for data utilization. We can also construct an IDS like the one introduced here.

Please contact us if you have any questions about IFC.

Consult with an IFC Professional

OpenAEC

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