The Object Constraint Language: Getting Your Models Ready for MDA, Second Edition

Uml

Enterprise Patterns and MDA : Building Better Software with Archetype Patterns and UML (Addison-Wesley Object Technology Series)

Format: Paperback
Author: Jim Arlow
ReleaseDate: 22 December, 2003
Publisher: Addison-Wesley Professional
Rating:

Valuable in many ways.
The archetype idea, intermediate between a general design pattern and a specific application, is a valuable one. Nominally, this book presents "archetype patterns", using UML and an extended case study. In the case study, it's a set of business meta-objects, operations, and organizing principles. In presenting the archetype abstraction, those objects are spelled out in enough detail to create a useable framework for routine business needs.

The archetype mechanism is also spelled out in great detail, almost wholly within the UML framework. By itself, this won't be enough to convince any UML doubters about UML's flexibility. Taken as one among many UML applications, however, it's very compelling. It's also the first reference I know that gets down to cases in applying MDA - an interesting view. I fault the technique for only two things. First is a slight dependence on a specific CASEproduct, ArcStyler. That reliance never turned all the way into an advertisement, so I'll let it pass. Second is a baffling section on "rules. " The rules and rule mechanisms make sense, but inexplicably seem to re-create the features of the OCL.

Two extras make this presentation very attractive. First is the mention of "literate programming," tying the UML tool suite to user documentation and design documentation. They specifically note XML and DocBook, existing standards, as the vehicle for integrating prose and technical parts of the model. Bravo! Even if their LP tools are weak, use of the idea is a real strength. The second extra is a pervasive awareness of standards. Money is phrased in terms of ISO 4217, nations in terms of ISO 3166, books in terms of ISBNs (ISO 2108), and on and on. Far too few programmers realize how many of their software requirements are already spelled out in external standardslike these, so the consciousness-raising exercise is a good one.

This is an excellent resource, not just for its business objects and not just for its UML case study. The author treat even personal names (table 4. 4) with more care than I've seen anywhere else - that care pervades the whole book, and is a lesson in itself.

//wiredweird.

Great practical material instead of esoteric theory...
This is another one of those books that I thought would deliver one thing and instead produced much more than I expected. Over the last month or so, I've been reading Enterprise Patterns And MDA - Building Better Software With Archetype Patterns And UML by Jim Arlow and Ila Newstadt (Addison-Wesley).

Chapter breakdown: Archetypes and Archetype Patterns; Model Driven Architecture with Archetype Patterns; Literate Modeling; Party Archtype Pattern; PartyRelationship Patter; Customer Relationship Management Pattern; Product Pattern; Inventory Pattern; Order Pattern; Quantity Pattern; Money Pattern; Rule Pattern; Summary; Archetype Glossary; Bibliography; Index

Now, when I requested this for review, I was expecting something in terms of programming patterns and technical material. What I got was a great business tool for modeling typical business objects and transactions. The authors take a business concept like Inventory, and they build a model around it. The model is an archetype, or a entity that exists in some shape in every business. Through UML diagrams, you'll see all the parts that make up the archetype and how to take the parts you need to build your own version of the entity. While the Inventory model is very comprehensive in the book, you can also pull the pieces you need to model the reality that exists in your own business.

There's some very practical benefits you can gain from this book. If you're building an application and need to track a customer (for example), you can turn to the Party model and see all the parts that make up that type of entity. This will help you to understand all the data elements that make up a Party, such as address (web, email, telephone, geographic), organization, person/gender/ethnicity, relationship, etc. These are elements you might think of and/or remember to include, but having the model there helps you get it right early on.

If you're a business analyst, you will really get your value from this book. And if you're a developer who also has to design the systems, you'll look like a wizard when you complete a solid design with features the customer didn't even realize they needed.

Modeling patterns worth the price alone
This isn't an MDA reference. The MDA in the title of this book probably overstates the amount of MDA related content in the book. There is one small, but well written chapter on it.

But that's a minor quibble. The real value of this book, and the bulk of the book, is in the third part which gives in depth models for the common enterprise application requirements. They start with an excellent object model for a 'Party' (as in a contact database), and continue on at the same level of depth for other common entities and processes, such as orders, payments, purchase orders, business rules, monetary values.

These patterns are probably too in-depth for a small business application, but they serve as an excellent starting point that you can trim to create a model that has the right level of complexity for your application. Don't let the big title of the book fool you. You can find books on how to write SQL, and generally how to model a database for a given problem domain, and other books on how query the database and make transactions. The value of this book is in giving you recipes for models for the basics of your application.