It could be years before web services live up to their full potential, according to analysts, vendors and early adopters.

Martin Butler, president of analyst Butler Group, warned companies not to invest in web services too quickly, unless they have important reasons to adopt. Even then, taking a measured approach is critical, he added.

"Caution is the keynote," he told delegates attending the analyst group's web services symposium in London. "Web services is a long haul - the dream of being able to connect systems in a real-time manner will not materialise for many years."

Butler said a number of areas surrounding the core web services standards of extensible markup language (XML), universal description, discovery and integration (UDDI) and simple object access protocol (Soap) still need to be expanded and developed if the technology is to succeed.

"Web services needs surrounding infrastructure, such as charging models and the development of grid computing. Strong parallel technologies are still developing," said Butler.

Mark Quirk, head of engineering for .Net at Microsoft, agreed that current web services have a number of shortcomings.

"Our number one priority is improving security," he said, adding that reliable messaging and transaction support are also areas in need of improvement.

Quirk also admitted that applications for Microsoft .Net have been slower to evolve than originally expected.

"Over the last two years, we've seen the reality that everyone will take time to get used to web services. In particular, consumer use is further out than we expected," he said.

At present, Butler said, web services are finding their greatest use within companies as a means of improving integration, through small experimental projects.

David Keene, Oracle product manager, said he had seen significant use of XML, Soap and web services description language (WSDL), but fewer implementations of UDDI, required for discovering web services across organisations.

Oracle has developed a web services implementation for Infomedics, a Dutch healthcare firm.

Adrien Rietberg, chief operations officer for Infomedics, said one problem for web services is inconsistent support for standards across applications.

"As this is so new, we found that not all products support features such as Soap messaging. We have used J2EE as a consistent and mature base to support future developments," he said.