SOA flexible, like Lego

Service-oriented architecture (SOA) is defined slightly differently by the various vendors that play in this space. It can be most simply defined as "a collection of services that communicate with each other. The services are self-contained and do not depend on the context or state of the other service. They work within a distributed systems architecture."*

This means that new or existing applications can be developed or redeveloped as services and used individually or separately to enable new services without the need for the organisation to build or buy and integrate new software.

Says Business Connexion CTO Andy Brauer: "When approached correctly, SOA is about structuring code in such a way that it resembles Lego blocks. When a new service is required, many of the blocks can be re-used without having to start from scratch. Re-usable code gives a business agility and flexibility from the back-end, and allows it to adapt quickly to changing market conditions."

The implications of this are significant. Says Dariel Solutions executive director Greg Vercellotti: "In short, it is no longer necessary for businesses to feel pressurised into buying all their systems from the same vendor in the hope of avoiding integration problems. With an SOA approach, organisations can choose the applications best suited to their needs, certain that any interoperability will be handled by their SOA middleware. SOA provides a means of leveraging existing legacy functionality and effectively reduces development times and risk for new applications. Furthermore, it allows organisations to leverage services provided by other organisations. As such, CIOs are turning to this to solve various integration and functionality problems."

An example is the ability to include Google maps in your own applications. This is made possible by the fact that Google exposes a mapping service via Web services and makes this freely available.

"This concept is known as a 'mash-up` and is becoming very common," Vercellotti adds.

Aside from solving long-standing integration issues, SOA also reduces integration costs. It reduces business risk, if only by allowing the business to re-use working components and not force it to rely on unproven new tools. SOA increases business response time as new services can be rapidly provisioned using existing components, and, obviously, allows the business to derive greater returns from the assets it has already invested in through being able to re-use existing applications, including so-called legacy applications.

Beyond the hype, however, what has SOA actually done to date? Says Vercellotti: "SOA has proven to do a number of things, most notably, confuse people. The notion of SOA is overused and over hyped by vendors, but if you look at something like Google, the success of the approach is obvious. By developing its systems using SOA, Google has made it possible for others to use its functionality freely and at no cost. SOA has become one of the prime enablers of the so-called Web 2.0 phenomenon and, as such, applications that leverage functionality from several sources will continue to emerge."

SOA is about structuring code so that it resembles Lego blocks.

Andy Brauer, CTO, Business Connexion

CA senior solution strategist Wilhelm Hamman says SOA enables IT departments to roll out and integrate new features and applications that support the business quickly and with relative ease. This, he says, in turn increases the flexibility of the organisation.

Notes Progress Software SA MD Rick Parry: "We have seen developers enjoy productivity gains of between 200% and 300% using SOA. But there is a caveat: the promise of SOA depends to a great extent on a robust backbone."

This backbone is the enterprise service bus. According to Wikipedia: "An enterprise service bus is an emerging standard for integrating enterprise applications in an implementation-independent fashion, at a coarse-grained service level (leveraging the principles of SOA) via an event-driven and XML-based messaging engine (the bus)."

Says IBM business development manager for Linux, Open Standards and SOA, Joe Ruthven: "The enterprise service bus [ESB] is a core element of any SOA. ESBs provide the 'any to any` connectivity between services within your own company, and beyond your business to connect to your trading partners."

CIOs should care about SOA, says Clive Hatton, senior consultant at RealIRM, because it "promises a more flexible way to integrate applications and an industry-accepted approach to application integration".

The notion of SOA is overused and overhyped.

Greg Vercellotti, executive director, Dariel Solutions

That all the major software vendors, from Oracle to SAP, are service-enabling their products is also a good indication that SOA is the way to go. That SOA hasn`t appeared to take off in South Africa to any great degree has more to do with the fact that many companies are investigating and planning SOA implementations, or are in the process of rolling out, and not yet ready to publicly declare what has been done and why. SOA is also not a point solution; one cannot simply implement it and leave it.

Barry de Waal, GM of the BEA and ILOG business unit at AL Indigo, points out that it is very important to understand that SOA is a journey and not an event.

"The successful adopters of SOA will be those that plan their journey well but don`t fail to actually embark on the journey. One of the first points that will be noticed will be the agility with which the adopters will be able to bring new projects to market. In the very competitive market that we live in, one of the biggest benefits will be the ability to react and effect changes as and when the market requires it."

Hannes du Plooy, e.com Institute information management manager, believes one should look at SOA as a long-term life cycle.

"As you implement new systems, you will have to change your SOA implementation. The most important thing is to get a strategy in place to determine how you plan to look after it, what feeds into it and what it connects to, particularly because you will not make use of all of the aspects of SOA immediately."

HP Software business unit manager Lenore Kerrigan adds a word of warning: "To ensure the success of an SOA initiative, it is imperative to have an effective governance model to address the processes and policies around SOA. Business is becoming more technologically literate, and if IT doesn`t step to the fore and drive such initiatives, business will. Don`t let SOA stand for State of Anarchy in your organisation!"

What can we expect beyond the hype? Dariel`s Vercellotti says it`s anyone`s guess. "The 'mash up` style application will most probably become ubiquitous, leading to more applications requiring broadband, since organisations will be working online continuously. The consolidation of portions of SOA into common and ever-present software will also affect the business` view of SOA.

"Additionally, organisations will begin to leverage their existing software assets more effectively and will demand SOA as a prerequisite for large applications purchased to facilitate integration with other enterprise systems. As such, the ongoing business requirement for integration and software market forces will affect how organisations invest in developing SOA. The SOA hype will soon go away and organisations will get on with the business of implementing the approach, as it is definitely here to stay."

This is one thing that is certain: SOA is, indeed, here to stay. While South Africa may be lagging Europe and North America in terms of roll-outs, SOA certainly hasn`t passed us by. Rather, it will have an effect on end-user organisations and the industry itself for some time to come.

* DM Review magazine (www.dmreview.com)