Recently, I was interviewed by a freelance journalist from ComputerWorld. Just in case I only get a one line quote, here are the questions and my written answers.
Enjoy!
Murray
The SOA Integration Ninja
1. What is new in the area of keeping legacy systems going?
Adapters for legacy technology are routinely being used as wrappers for legacy functionality, promoting the reuse of this functionality within new and different business processes. While adapters have been available for legacy systems for many years, it has only been recently that standards for these adapters have been ratified. The WS-I (Web Services Interoperability) specification and the Web Services SOAP standards have been embraced by the software industry. Software vendors are just now releasing adapters, based on WS-I and SOAP, that allow legacy systems to ‘play nice in the integration and SOA sandbox’.
2. With web front ends, is there any reason to retire legacy systems rather than just giving them a new UI?
Most legacy systems were built to perform a specific set of functionality in a controlled and governed environment. When this functionality is exposed as services through a new web front end, the additional burden this puts on the underlying infrastructure and increased traffic may necessitate replacement of the legacy system rather than give it a new UI. Web front ends are often just lipstick on a pig. But you don’t shoot the pig that keeps winning you blue ribbons at the fair and you don’t retire your legacy applications when they continue to add value.
3. Is the retirement of IT workers leading companies to update their systems because they can no longer easily find personnel?
Not only is the retirement of workers causing IT shops to update their systems but also the rapid pace of change that has been embraced by the business. Users of corporate systems have come to expect the jazz of rich user interfaces and the experiences promised and delivered through web 2.0 technologies such as BLOGs and RSS. The ‘green screen’ is dead and is not tolerated for long amongst even the most inexperienced User that has spent more than a few hours browsing the internet, including Google, MySpace and YouTube. Business users have come to expect that their corporate applications can change at the pace of business. This pace is furious.
4. How should one decide whether to retire an old system or keep it running?
There is no magic or advanced formulae that should be used make the legacy retirement decision. A simple cost-benefit analysis weighing the pros and cons is still the preferred method of decision making. These decisions are almost always based less on the technical merits of the legacy system and more on the non-tangible aspects such as the projected lack of qualified technical resources for support and maintenance, vendor relationships and increasing total cost of ownership.
5. What are some mistakes people make when extending legacy systems?
When extending legacy system functionality, people often turn to the experts who wrote the system in the first place. These individuals are then asked to write code in a language unfamiliar to the majority of the remaining IT shop. While this seems the most cost effective approach at first, it is this fatal mistake that continues to tie companies to the legacy systems and the business processes it is able to support. The new paradigm is to leave the existing legacy functionality as-is and extend through standards based service interfaces. These services are then made available to orchestrate within agile workflow modeling software. The extensions are written in the latest technologies such as J2EE and .NET, with rich user interfaces and hopefully, breathe new life into the legacy systems value proposition.
6. What are some best practices they should follow?
A set of best practices, known as SOA (Service Oriented Architecture) has recently been adopted by the IT industry. SOA is based on the realization that change is ever present, moves at internet speeds, and that systems should be built in anticipation of having to change. The SOA vision of business and IT agility is realized through the introduction of a services layer that is based on industry ratified standards. These standards cover event-driven architectures, JMS, Web Services(SOAP), XML, BPEL, and industry standards schemas. Organizations should look to expose their legacy systems functionality as services using these standards.
Labels: SOA Legacy Integration Ninja Extending
