The Unified Modeling Language (UML) is one of the most exciting and useful tools in the
world of system development. Why? The UML is a visual modeling language that enables
system builders to create blueprints that capture their visions in a standard, easy-to-
understand way, and provides a mechanism to effectively share and communicate these
visions with others.

Communicating the vision is of utmost importance. Before the advent of the UML, system
development was often a hit-or-miss proposition. System analysts would try to assess the
needs of their clients, generate a requirements analysis in some notation that the analyst
understood (but not always the client), give that analysis to a programmer or team of
programmers, and hope that the final product was the system the client wanted.

Because system development involves communication among people, the potential for error
lurked at every stage of the process. The analyst might have misunderstood the client. The
analyst might have produced a document the client couldn't comprehend. To add to the
mess, analysts often created wordy, voluminous requirements documents that were difficult
for others on the project team to work with. Paradoxically, the sheer weight of these
documents often allowed important requirements (and dependencies among requirements) to
slip through the cracks. Thus the results of the analysis might not have been clear to the
programmers, who subsequently might have created a program that was difficult to use and
didn't solve the client's original problem.
Is it any wonder that many of the long-standing systems in use today are clunky,
cumbersome, and hard to use?

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