Mainframe systems are playing a key role in many SOA (service-oriented architecture) projects, according to a study released this week by IBM user group SHARE.

Mainframes like IBM's System z are integral to SOA almost by default because they contain a large portion of the world's business information, the study suggests. Thirty percent of respondents who work for companies with 10,000 or more employees said between 51 percent and 75 percent of their company's data is managed and stored on a mainframe, according to the study.

Meanwhile, nearly 23 percent of respondents said their company is undergoing a SOA project, and another third said a SOA is in the planning or consideration stages.

Thirty-seven percent of respondents said they are pursuing an enterprise-wide SOA, but in most cases, the projects are confined to niche instances, such specific lines of business or divisions or within applications.

"Many of the applications that need to be SOA-enabled are mainframe applications," said Pamela Taylor, vice president of strategic development for SHARE and a solutions architect for a subsidiary of a Fortune 50 company. "System z tends to be absolutely critical to deployments."

While mainframes play a dominant role in hosting an enterprise's data, companies' interaction with that data faces constraints. At least 50 percent of the companies surveyed use hand-coded scripts to push mainframe-based data to other databases or platforms, according to the study. Such scripting is hard to maintain, particularly if the programmers who wrote it leave the organization, the study notes.

IBM has aligned System z with SOA.

The study notes that SOA can strain systems, such as through its use of XML-based messaging. "Rather than acquire more server hardware to attempt to address growing SOA performance issues, mainframes may represent a more cost-effective option for leveraging existing resources," the study states.

In turn, the abstraction layer a SOA provides can help enterprises more easily tap their existing mainframe applications and data, the study notes.

Sales for System z fell last year but IBM is banking on the launch of its next-generation mainframe in February.

Some 431 SHARE members responded to the survey, which was conducted by Unisphere Research. About 48 percent work for companies with 1,000 or more employees, and 26 percent of respondents' firms have more than $1 billion in revenue.