- Building Lifecycle Interoperable Software -

Project Brief

Original: 15-June-1999
Updated 09-August-2002


Since its formation in September 1995, the International Alliance for Interoperability (IAI) has published 3 major releases of the Industry Foundation Classes (IFC). These releases consisted of specifications defining an object based data model for the AEC industry. The IAI’s goal was that these specifications would support software implementation by multiple vendors, such that the software of these vendors could exchange and interoperate on a commonly understood data model of a building project.

Although IFC specifications were available since late 1996, implementation activity prior to the BLIS project was very limited. It seemed that most companies were waiting to see what the large CAD vendors would implement.

The BLIS project was conceived as a way to initiate the next logical phase in the widespread adoption of an object data model standard for the AEC/FM industry. It is our hope that the implementation and cooperation commitment by a large number of software vendors will break the 'wait and see' delays to date.

In BLIS implementation work to date, the majority of project participants have argued for a pragmatic approach to support for standardized data objects. The basis for this pragmatic approach is a small set of end user 'use cases' that BLIS Company applications will support flawlessly. In order to achieve this, these 'use cases' and associated object sets have been defined in great detail. These object sets constitute a logical (pragmatic) subset of the current IFC release (Release 2.0). To date, no significant modifications to the IFC object definitions have been necessary. However, the BLIS organizations have agreed in advance: should we need to add or modify an object type, we will (a) develop project consensus on these modifications, (b) implement them and ship the products for validation by end users, and (c) propose IFC changes back to IAI after that validation.

Project initiation meetings were held during July 1999 – in 4 locations. These were: USA (Portland), Europe (Helsinki), Japan (Tokyo), Australia (Melbourne).

At least two dozen additional meetings have been held at several venues since. The BLIS project is growing quite rapidly now, with over 50 participating organizations. More importantly, with 8 Developer tool sets, over 30 end user applications released or in testing, and end user pilot projects in Australia, Europe and North America, the BLIS project concept has proved to be quite successful in transforming the concept of IFC into real interoperable software for the AEC industry. Finally, the process efficiencies and product quality improvements seen in manufacturing can be realized in AEC projects.

Relationship to IAI

BLIS is a coordination project -- coordinating the implementation efforts of vendors seeking to support IFC R2.0 in applications that will ship in 2001. While the project participants are IAI member companies, BLIS is not an IAI project. IAI projects focus on requirements and specification of the IFC model. BLIS supports implementation of IFC specifications in software products. Participation in BLIS is a decision by each company invited by the existing participants. It is not related to other decisions these companies make with regard to participation in IAI projects.



Schedule Overview

The following implementation phases are averaged over the group. Some will be early in these timeframes. Others will be later. They are included only as a general guide. Schedule for any particular company will be agreed with the BLIS partners working with that company.


End User 'Use Cases'

The BLIS model ‘Views’ of IFC were designed to support the following end user ‘use cases.’

  1. Design ß à Design (geometry view)
  2. Client briefing/space planning à Architectural design
  3. Architectural design ß à HVAC design
  4. Arch/HVAC Design à Quantities take off / cost estimating
  5. Arch/HVAC Design à Thermal load calculations / HVAC system design
  6. Arch/HVAC Design à Construction management/scheduling