Ng Andrew – Assignment B2: Chapter 3 - Interoperability (Group B)

Delayed submittal due to being hospitalized and hand injury.

Chapter 3 – Interoperability

Interoperability depicts the need to pass data between applications, allowing multiple types of experts and applications to contribute to the work at hand. The data is passed between applications by the standardization of file formats. Same or similar file formats allow for programs to be compatible with each other. The data models developed would support product and object model exchanges within different industries by the ISO – STEP international standards effort. [1] Geometry, relations, processes and material, performance, fabrication, and other properties used for design and production can be transferred more fluidly from one application to another. With more fluidity between programs, efficiency in a project increases.

One example of a formalized file format or language is EXPRESS. EXPRESS enables applications that have multiple redundant types of attributes and geometry to export and import different information from each other to describe the same object [1]. Design and construction benefits from this as the design process requires people to work together. Each certain step passes on information from one phase to the next. For example, when a design of a building is drafted, it must be passed onto someone else such as the contractor who then works on shop drawings. The contractor may or may not use the same program to do so. Other examples include the analysis of some system in a building. Structural and energy analysis, cost estimation, scheduling, and other aspects are worked on in a project and are typically done by different parties involved. The data passed between the parties must somehow be accessible as the parties have different methods to accomplish their work. The huge benefit of interoperability is that it eliminates the need to replicate data that has already been generated. By using data already made and instead of remaking it, work flow is made more smoothly. Architecture and construction go hand in hand, and saving time in this industry can save a lot of money.

By bringing numerous companies together, Robert Fulton, a NASA representative, facilitated the creation of a public domain exchange format for CAD software. He demanded that information can be shared between applications. I found this action to be extremely forceful but needed. Fulton being in NASA has the position to make such demands made me chuckle a bit. His action, however, created data exchanges in four main ways. [1]

1.       Direct, proprietary links between BIM tools

2.       Proprietary file exchange formats, primarily dealing with geometry

3.       Public product data model exchange formations

4.       XML – based exchange formats

These four methods were how the companies exchanged data for their CAD software.

The AEC also made data exchanges more compatible. Common file formats are shown in the table below.

These formats designed to show some form of shape or geometry became compatible starting around the mid-1980s [1]. After many data exchanges of complex models between Europe and the US, the International Standards Organization (ISO) in Geneva, Switzerland, initiated TC184, a technical committee to develop STEP, Standard for the Exchange of Product Model Data. This increased communication of what the parties involved want to accomplish in some project. The Industry Foundation Classes (IFC) also was developed to make consistent data representation of building information for exchanges between AEC software [1]. The library of objects and property definitions enabled the data to be generated properly when retrieved from one application and placed on another. A main benefit the IFC provided is building information analyzation. It covers the whole building lifecycle. In the design phase, structural and mechanical elements are simulated with the different extensions. The IFC addresses any limitations between the file extensions and with its next releases covers the issue. They respond to the users and get their input for the developers to come up with solutions. With BIM tools, IFC translators revert the shapes made into data to be exported and rebuilt in another interface. The data can be exchanged between programs such as Revit and Bentley Structures. This makes life easier for a structural engineer as he is given different options to approach his design or analysis.

Source:

[1] Eastman, C., Teicholz, P., Sacks, R. and Liston, K. (2008) Interoperability, in BIM Handbook: A Guide to Building Information Modeling for Owners, Managers, Designers, Engineers, and Contractors, John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470261309.ch3

Comments:

Taryn Francischetti – Reading your explanation of the concept of families on BIM software was very interesting. As users can draw shapes and lines, the shapes are predefined. I find this very efficient as there won’t be time used to go back and declare what lines are which feature. This would save time in the construction industry.

Paulina Gawor -  When you mention about poor interoperability costs, I started to think about all the dreadful expenses that can add up. Poor communication and applications that do not work together or can’t share information can lead to unnecessary wasted time. It also would most likely increase stress in the work place and many other negative effects would occur as a result.

Mengnan Yang – BIM models is great tool for contractors. Collaboration between the parties and between the steps you’ve mentioned increases the efficiency of workflow. With BIM estimation of costs and visualization to explain the design, a lot of benefits for the parties involved are created.