Besides general purpose designs, patterns can be specific to particular areas of computing. Martin Fowler's Analysis Patterns: Reusable Object Models contributes to the literature of patterns by defining over 70 patterns derived from the health care and financial areas. The book begins with some intriguing patterns from the business world include the Party and Accountability patterns, which define the players in organizations and whom they report to. A considerable number of patterns are drawn from the health care industry--principally doctor-patient interactions--with patterns such as Observation, Measurement, and Protocol. Obviously, these will be most applicable to object modelers who work in this industry (though, of course, patterns can often be used profitably in other fields).
The patterns for financial markets will probably be more interesting for most readers. Fowler defines a Transaction pattern (and related patterns) as well as several for the accounting of objects. He moves on to modeling stock markets with patterns for Portfolio, Quote, and Scenario (which defines how a price for a stock is defined for a given moment). Interestingly, he defines patterns for Forward Contracts (for derivatives) as well as Options, and so takes on a complicated area of so much activity in today's financial markets.
The book benefits from the author's considerable design experience in these fields. The author defines each pattern in both text and in software-engineering diagrams, but rarely provides implementations of these designs, Implementations that are included are in Smalltalk, making this a book for those experienced with object design. --Richard Dragan
