Nerson promotes a descriptive method that addresses both analysis and design issues. A case study shows how the technique works and how it fosters the production of reusable components. Although the paper contains a useful exposition of the system design concepts used by the author, it has some unfortunate flaws. The concept of class clustering is never adequately explained or justified.
Some concepts used in the paper are redundant and confusing.
For example, association and aggregation are seen as subtypes of a client-supplier relationship. The problem is that association and aggregation are more abstract than client-supplier, not less. Although internal and external events are mentioned, these concepts are never put together with others needed to model the dynamic aspects of a system, such as transactions and discrete time, or differential equations and continuous time. The argument is made that this conceptual scheme, known as better object notation, is somehow qualitatively different from more traditional techniques. On the basis of this paper, it is not.