A Review of the SOA Practitioners Guide

The SOA Practitioners Guide is a thorough 3 part document covering all aspects of SOA. Much of what is discussed in this guide is not specific to SOA but a more general advocacy of best practices in IT development. Thus the Guide looks a development methodologies, portal technologies, support infrastructure, project planning and a number of aspect that are not pre-requisites to having SOA in place but support the establishment of successful SOA.

The three parts of the Guide are:
· "Why Services Oriented Architecture?"
· "SOA Reference Architecture"
· "Introduction to Service Lifecycle"

The first part was more a summary of what was to covered in the second two parts than a justification of SOA. I have read better and clearer justifications of SOA.

The Reference Architecture part is well presented and goes methodically through the layers explaining the various architecture options available. I am interested how different authors divide up an SOA. In the Guide the layers are:
· Web Application Tier
· Service Tier
· SOS Frameworks
· Application Tier
· Enterprise Security
· Business Service Management
· Services Oriented Infrastructure

Often when I read marketing literature or documents on IT tools I get the impression that these documents are written for global multinational organisation with huge IT budgets and hordes of technical people. This is one of those times. The array of tools a good SOA shop needs and the array of technologies an IT organisation is expected to master is mind-boggling. It is amazing that a medium sized enterprise gets any software development done at all. Occasionally I would like to see advice for small and medium organisations.

The third part of the Guide covers a number of design and development issues. It goes through the Software Development Lifecycle and looks at how SOA impacts on each stage. There is still a strong emphasis on tooling and technologies in this part. In this section there is an emphasis on Service Component Architecture (SCA). This is a fairly recent standard for bundling up services into components. According to Wikipedia version 1 of this standard was released in March 2007. I found a good summary of SCA was "Introducing SCA" by David Chappell.

The Guide is presented with a number of good examples, many dot-point lists and a huge number of references to other technologies and tools. A glossary of acronyms would have helped.

Writers on SOA seem to divided between those that focus on Web Services and those that embrace the diversity of different ways of doing SOA. The Guide authors (ten of them) are from the latter category. A number of alternate technologies and supporting technologies are discussed.

In conclusion I can recommend the SOA Practitioners Guide to anyone wanting to get a wide-ranging survey of current practice in SOA and software development.

Reference:

Durvasula et al., SOA Practitioners Guide, Sept 2006, http://colab.cim3.net/file/work/SOACoP/2007_05_0102/SOAPGuide/

Chappell, David, Introducing SCA, July 2007
http://www.davidchappell.com/articles/white_papers.html