Workshop on
    Composability Issues
    in Object-Orientation

Tuesday, July 9, 1996

- - workshop report - - book publication
- organizers - participants - contact-info - CFP - planning
- attendance - papers - related workshops - links


Lodewijk Bergmans (University of Twente / STEX bv, The Netherlands)
Pierre Cointe (Ecoles des Mines Nantes, France)

The participants

Information about all participants, their position papers and proposed workshop topics is collected here.


You can contact the organizers through e-mail at the following address: ( mail now). More elaborate contact information can be found at the end of this page.

Call for Participation

Recently, the area of composability in object-orientation gains more interest, as it becomes more apparent that the 'conventional' object model does not sufficiently provide support for object composition.

Composability is the ability to put together a piece of software from several components. This is an essential property for building large and complex systems as it enables modularization and separation of concerns. Well-known techniques for composability are inheritance, delegation and part-of relations, which compose behavior, data structures and/or states to define new objects.

One of the issues in composability is that components (objects) are a combination (composition) of specifications for several independent aspects and concerns. Examples are behavior, data structure, data values, synchronization, constraints, etc. On one hand these specifications must be composed into a consistent object specification, on the other hand, when composing a system from existing objects, we may be interested only in particular aspects from these objects.

In addition, the composition semantics may be different for each aspect. As a result, it is in practice often very difficult or impossible to achieve a particular composition. For example, inheritance is a mechanism for composing new objects from one or more existing specifications. Conventional inheritance defines semantics for composing behavior and data structure, respectively from the inherited and newly defined methods, and from inherited and newly defined instance variables. Obviously, this is insufficient if application objects involve more than these two aspects.

The goal of this workshop is to define the research area and the state of the art in composability of objects, and to come up with a list of open problems. As an indication, we mention some relevant topics:

Workshop Planning

During the workshop, after (brief) presentations and general discussion, we intend to split in small groups that focus on topics that the participants have indicated before, we finish with conclusions from these groups. The goal thus is to have an (inter)active workshop instead of just a series of presentations!

The preliminary Workshop Agenda is available now.


Participants should submit a short (3-6 pages) position paper. The position paper should preferably propose one or more open problems in composability by providing a clear motivation. The position paper should also include, or be accompanied by, a list of topics to be addressed during the workshop. Submissions in electronic format (Postscript or plain ASCII text), sent by email (now!) to are strongly encouraged. Position papers should be received by May, 31, 1996. Notification of acceptance will be by June 20th, 1996 (Note that we extended the deadline).

The received topics will be collected and a selection will be made by the organizers and participants through e-mail discussions. Based on the received position papers and the selected topics a few speakers will be invited, based on their coverage of these topics.

The position papers

The position papers are available here. They are all in postscript format. They should be readable and printable by everyone.

Book Publication

The ECOOP '96 Workshop chair, Max Mülhäuser, has arranged the possibility of publishing ca. 60 pages for this workshop in a shared volume with proceedings from most other ECOOP workshops. These will be published in the following book:

More information about the contents of the book chapter that is dedicated to the composability workshop can be found in the

Related Workshops

Workshop On Component-Oriented Programming: Adaptability in Object-Oriented Software Development Workshop

Pointers of Interest


This page is (hopefully) maintained by Lodewijk Bergmans