SOAs (service-oriented architectures) are needed to accommodate the distributed nature of today's businesses, said an IBM official at the SD (Software Development) West 2005 Conference on Tuesday.
Businesses that used to be monolithic now operate in an increasingly distributed fashion, dealing with customers and suppliers in a much more flexible environment, said IBM's Jim Rumbaugh, a distinguished engineer at the company and a founder of the Unified Modeling Language. Stability is no longer the mode of operation for businesses; change is, according to Rumbaugh.
"Because business is changing, the software infrastructure to support it [has] had to change in all these same ways," Rumbaugh said.
Rumbaugh outlined four key points for evolving businesses in building a software infrastructure:
- A component business model is needed, with components providing services.
- IT architectures must change to support service-type architectures.
- Mapping of architectures needs to be automated via MDA (model-driven architecture) technologies.
- Monolithic-style development needs to be avoided in favor of iterative development.
Standards are critical to deploying service-based systems and also for interconnectivity, Rumbaugh emphasized. "First of all, we have to accept standards, including open source standards, for interoperability," he said. "Companies that will not participate in a standards-based environment are just going to go out of business."
Although the term SOA is vague, it does represent an attitude in how to go about deploying systems, according to Rumbaugh. "The real goal is to get flexible connectivity among the parts so you can make changes easily," he said. Web services provides the first example of an SOA, according to Rumbaugh.
An ESB (enterprise service bus) provides connectivity between different systems in an SOA, Rumbaugh said. Legacy systems must be accommodated on the ESB.
"We're not going to redo a business all at once so we need some on-ramps to the bus to bring legacy systems online," Rumbaugh said.
Systems in an SOA also must be loosely coupled. "You really need a plug-and-play mentality to building this kind of system," Rumbaugh said.