Software Engineering Documentation

BON - Business Object Notation. The BON method for analysis and design of object-oriented software is a means of extending the higher-level concepts of the Eiffel programming language into the realm of analysis and design aided by a graphical notation akin to but different from UML.

BON provides a textual and graphical notation for modelling the static and dynamic structure of OO software:

• BON has strong support for providing precise specifications of re-usable, industrial strength components via Design by Contract (preconditions, postconditions and class invariants), which includes subcontracting via the inheritance relationship. See example below.
• It supports a seamless method for turning software construction from specification to implementation into a single continuous process.
• It supports reversibility which is the ability to go back from implementation to specification.

The graphical shapes of BON can be drawn using Microsoft Office Visio (available on Windows workstations in the Prism Lab or for your Laptop – see links below).

• Using the BON Visio Stencil (Visio 2013 and later), we can draw BON class and dynamic diagrams. A BON/Visio manual is available describing how to use Visio for the BON diagrams.
• This is the https://wiki.eecs.yorku.ca/project/eiffel/_media/bon:bon-visio-stencil-original.zip for Visio2010.

Here is an example of a contracted class CITIZEN using the BON notation:

In BON diagrams, use mathematical notation to express contracts. See the BON textbook for more examples.

BON is described in depth in the book Seamless Object-Oriented Software Architecture, Prentice Hall, 1994, by Kim Waldén and Jean-Marc Nerson. The textbook is now out of print but available from the BON website as a pdf.