| 1.5 XML Bolt-Ons There is also another factor driving XML implementations: imposed standards.
Recently, the U.S. Depository Trust Company (DTC), which handles securities trading
settlement in the USA, and SWIFT, the international financial transaction network,
announced that next year they will begin accepting data exchanges via XML documents.
Although the legacy, fixed format data exchange will continue to be supported for the
foreseeable future, it is clear that not moving to XML based exchange will impose a
steadily increasing burden for users of their services in the next few years. This is a
shot across the bow for companies that don't have plans for XML data exchange. Companies
that don't embrace XML either for its benefits or to avoid being left behind
technologically may be forced into it by their data exchange partners.
However, in this case, it makes sense to consider a simple
XML bolt-on solution. The few file or message interface formats required for external
communication with an application that speaks XML certainly do not mandate the wholesale
retrofitting of the legacy application for XML. In this case, one could simply use an XML
genera-tion utility or write the code into the affected program or programs to create an
XML document in place of the old fixed record format. Deciding for wholesale use of XML
versus a sim-ple bolt-on is a management decision, not a technical decision. It is similar
to the decision to replace VSAM, for example, with a SQL database in order to capture the
larger benefits of the rela-tional database environment: data integrity at the logical and
context levels, and a loosely coupled interface between program and data. Why replace a
perfectly good file system or old database with SQL? If you have a good reason to answer
yes to SQL, then you have a good reason to answer yes to the wholesale use of XML, and
perhaps a few additional ones as well. As a practical matter, at first most sites will use
XML only at the interfaces with external applications. However, as the power of the XML
interface becomes clear and supporting tools become available, XML data exchange will
begin to be used for A2A integration, and eventually within applications as well. In fact,
we see this beginning to happen with some of our customers. |
