A Componentware Approach for the New Generation
of Business Applications in Construction
Corresponding Author: Zarli, Alain
Author(s): Zarli, A. (*), Buckley, E. (+), and Richaud, O. (*)
Organisation(s): (*) Centre Scientifique et Technique du Bâtiment, Sophia Antipolis cedex (France), (+) Building Information Centre, Dublin (UK)
[WHY] Networking technology and object-oriented distributed systems are today recognised as the foundations for concurrent engineering, in order to satisfy the fundamental requirements of complex information management, enterprise systems and fast reactive business, where applications have to allow to access remote critical data from desktops widely spread over the Internet, to support the browsing of data and documents by connecting to enterprise servers, to provide appropriate access privilege according users, partners or customers, etc.. Moreover, business is becoming increasingly adaptive, and enterprises must be able to modify with high flexibility their information systems. Thus, new applications make stringent demands for scalability, robustness, dynamic reconfiguration and integrated security solutions. This new generation of business applications to come will be N-tier architectures, based upon distributed objects that are a major evolution towards intelligent components, but are still not easy to integrate and mainly deal with distribution aspects . Component-based development is the next step in the evolution of object systems, and can help to deal with new development challenges.

[WHAT] To ease the realisation of business applications while masking the complexity of the underlying “plumbing”, the WONDA project promotes the concept of business objects (BO ) and software components representing the enterprise business model by encapsulating business rules and aiming at providing transparently secure access to diverse electronic content and applications. The main WONDA objective is to develop an open and secure framework for BOs supporting Intranet applications, electronic publishing and electronic commerce, achieving this by automating as much as possible the work involved in creating and deploying software component-based applications, wrapping existing systems and data for presentation as components.

[HOW] BOs are distributed objects (CORBA objects, considering OMG terminology) representing active things in a business domain. They enable a greater focus on business logic and application development, thus introducing a major enhancement for distributed infrastructures. But whereas CORBA provides a framework for distributed objects, a more elaborated framework to support BOs is required: in order to effectively, unambiguously and rapidly define BOs, WONDA builds upon CDL , which captures the semantics expressed in BOs and models attributes, operations, states, business rules, events and bi-directional relationships. From CDL specifications can be produced:

- The corresponding IDL specifications of BOs according to the WONDA framework, which is fundamentally oriented towards the distribution of BOs.
- Code in a target language (C++ and/or Java) to compensate the loss of semantics induced by the CDL/IDL mapping, based on the WONDA framework. CDL has a richer semantics than IDL and requires generating additional code to avoid loosing semantics.

Beyond CDL, BOs specification and implementation in WONDA will be investigated against emerging models, especially the future multi-language CORBA component model aiming to tightly integrate Java, EJB, and CORBA so that applications and objects can be used across more than EJB servers. Indeed, the CORBA model grants standard services layer for EJB to go against, and the complementary of these two models is a true potential basis for future large-scale component-based business applications. Eventually, a particular focus in WONDA is put as well on end users manipulation and multiple graphical views on BOs, through a Media Objects model and multi-modal GUI-oriented mechanisms, with notifications from BOs to Media Objects realised through a publish and subscribe technology, thus leading to loose coupling between Media Objects and BOs.

[Intended Use] WONDA aims at a better WEB integration to enable electronic publishing and commerce using BOs, and to foster a better industrial exploitation of the large information sources and enterprises databases accessible through the WEB, with a demonstration of results in the specific Building Construction domain. The WONDA framework will be open technically in terms of standards, configurability and modularity, offering a low entry level and unlimited growth path strategically important in offering SMEs a solution that they can afford, and supplying an incremental path which enables them to take small or large steps at a time towards a complete Enterprise Information System.

WONDA Project Information

The research and results presented in this paper have been funded by the Commission of the European Communities under the ESPRIT IV Program, Project EP25741 WONDA (Domain 1: Software Technologies). This work has been undertaken by the following partners: 
- BIC Building Information Center (Ireland) 
- CSTB Centre Scientifique et Technique du Bâtiment (France)
- DE Dassault Electronique (France)
- SNI Siemens Nixdorf Informationsysteme A.G. (Germany)
- TU Delft Technical University of Delft (NL)

The project represents 265 man-month of work for a duration of 2 years, and involves both research, developments and proof of concepts through the elaboration of pilots. It is expected to be a major step towards the delivery of WEB-oriented software components for the Building Construction sector.

 1 Particularly, Business Process Re-engineering (BPR) is hard to realise at that level.
 2 EP 25.741 WONDA: WOrld wide eNterprise DAta interoperability.
 3 The concept of BO is currently under standardisation by the OMG (Object Management Group), together with a standard framework for business applications.
 4 Object Management Group.
 5 Component Definition Language, promulgated by the OMG as the more advanced and powerful language to describe BO interfaces and specifications in an object-oriented manner.
 6 Also referred to as CORBA Beans.