OO Development's silent partner - repository technology critical in software development - includes related article on repositories and the year 2000 transition - Technology Information

Software Magazine, Feb, 1997 by Mary Hanna

Possessing all the glamour of household plumbing, repository technology seems destined to remain one of the most unappreciated components of the software development environ-ment. It rarely appears on a CIO's most-wanted list, due largely to its reputation for being expensive, as well as difficult to set up, propagate and maintain. Nevertheless, the technology may become as critical to the success of an object development effort as water pipes are to an efficient household.

That's the case at the Air Mobility Command (AMC) division of the United States Air Force, which delivers humanitarian supplies to sites worldwide. Loading cargo planes with the appropriate material and personnel and traveling to trouble spots is just the beginning. The real challenge comes once the planes reach their destination.

The effective use of an airfield requires a great deal of information about ground facilities, says Joseph Butchko, AMC project lead for business engineering at Sumaria Systems Inc., a Scott Air Force Base, Ill., consulting firm working with the AMC. "AMC planners need access to critical data about the airfield, such as runway length, number of hangars, availability of lodging and work space for the crew and relief personnel, as well as refueling and maintenance capability for the aircraft." In order to place such information at planners' fingertips, AMC's software developers stationed at Scott Air Force Base are working on a Location Capability Application, which will collect, store and update data gathered from sources such as commercial businesses and airway flyovers. The project is one of 27 applications underway designed to streamline AMC's mission-critical response to worldwide crisis situations as designated by the U.S. government. The projects are being developed using object-oriented techniques and each one requires a number of models -- dynamic models, logical data models for relational databases, domain-level models, and object models that define objects and their relationships.

However, unless the models can be shared by team members, they're of little use, Butchko says. "With upwards of 30 analysts, each generating multiple models, a repository is crucial," he adds. The development teams are using the InfoSpan repository from Metadata Management Corp., Vienna, Va., to complement their analysis tools. They use BPwin and ERwin from Logic Works Inc., Princeton, N.J., for modeling business processes and data-entity relationships, and Paradigm Plus from Platinum Technology Inc., Oakbrook Terrace, Ill., for modeling objects.

"We use Metadata's repository to hold final-version products, as well as draft models that are in the process of being approved," Butchko says. "We capture and then interrelate information from tools like Paradigm Plus, ERwin and Microsoft's Access."

Despite the benefits, AMC's software developers have found that using repository technology requires a huge commitment from developers and users alike. In the beginning, the project team encountered many of the stumbling blocks that plague other large projects -- uncertain user goals, vague problem definitions, difficulties selecting tools and changing vendor relationships. Keeping all the tools updated with the latest versions further complicated things. "To avoid big implementation problems," says Butchko, "the repository has to be flexible enough to handle new versions of software."

The upshot is that the team brought the repository online just a few months ago, after working on it for more than three years. "It has only recently been robust enough for the team to derive some benefit from it," he says. "We're still learning how to exploit the technology for reuse of analytic and design objects."

Not every firm has the resources and stamina to embark on massive repository projects like AMC's. In fact, most companies don't want to be bothered by technologies that require extra effort and specialized resources.

"There used to be a lot of talk about repositories being a technology-neutral way of exchanging information among tools," says Dick Heiman, research manager of application development tools at International Data Corp., Framingham, Mass. "But it never really worked out that way. People figured out the interchange for whatever tools were important to them, without resorting to standalone repositories."

In fact, some observers question whether standalone repositories have a future. "The old standalone repository model is difficult for many firms to utilize because the entire architecture must be learned before it can be used effectively," says Keith Short, advanced technology director at Texas Instruments Software in London. "In addition, the monolithic repositories lack extensibility, which makes them unable to handle component-based development."

As development becomes more dispersed across the enterprise, the standalone repository is giving way to repositories that come bundled with a single vendor or multivendor suite of tools. This new breed includes the Forte Application Environment from Forte Software Inc., Oakland, Calif.; the Key family from the Applications Development Division of Sterling Software Inc., Atlanta; System Manager and Deliverables Manager from LBMS Inc., Houston; and the Composer series from Texas Instruments Inc., Dallas. After all, a repository is not the most compelling reason for buying a tool. The business solution -- not its underpinnings -- is what sells.