# Seamless Object-Oriented
Software Architecture

— Analysis and Design of Reliable Systems

## History

The BON method was initiated by Jean-Marc Nerson in 1989, who presented early ideas in a tutorial at the second TOOLS conference held in Paris 1990. I became interested immediately because, in my view, all ongoing work about methods and notations for object-oriented analysis and design that I had seen presented in articles and conference tutorials so far, were all going in completely wrong directions. More or less all of them building heavily on some kind of entity-relationsship and/or use case modeling, all derived from traditional data modeling and functional decomposition.

I could not find a single article exploring the true power of the object-oriented abstraction, its unique ability to be used as a seamless modeling concept all the way from domain-level analysis down to executable code, and its perfect match with what was most lacking in software products (and still is), precise specification of each of its software components. BON was the first (and to my knowledge still the only) attempt in this direction , so I started to collaborate with Jean-Marc and teach BON courses at Enea to Swedish industry.

The BON technique was applied in several industrial developments over the next few years, and Jean-Marc published three articles in 1991-92. However, it soon became clear that more detailed documentation on the subject was needed if the ideas were to reach a wider audience, and in 1993 we decided to write a book about BON. The notation was cleaned up considerably, and a process model with standard activities building on our industrial experience was developed. We also put together a substantial section with carefully worked out case studies, and a complete grammar for a textual form of the BON notation.

The book was published in 1994 (with a Japanese translation following in 1996). Shortly after its publication, I was fortunate enough to be able to verify the design I had put together in the third case study of the book, concerning a transparent bridge between object oriented business models and an underlying relational database. A colleague of mine, Per Grape, and myself implemented this design as a general framework for a Swedish customer in 1995-96.

The framework, which is called MRF, has been successfully used by the customer for more than six years now, and I hope to write up a case history for publication on this site as soon as I get the time.

## Book text now available

Unfortunately the book went out of print by the end of 1999, and I have had constant requests for it since then by developers who have experienced the inadequacy of the omnipresent RUP/UML approach and are seeking an alternative. So it is with great pleasure that I can now at last (March 2003) give a positive response to all interested parties. The copyright has been transferred back to the authors by Prentice Hall, and we have decided to make the text freely avalaible.

The full book text (2 Mb) in pdf format can be accessed here. Some people have been asking for an electronic version of the BON textual grammar (see Appendix A, pp. 349-363 in the book) in order to build parsers for it. Here is a version of the grammar in plain Ascii format.