文档介绍：Generating Test Cases From Use Cases
by Jim Heumann
Requirements Management Evangelist
Rational Software
In anizations, software testing
accounts for 30 to 50 percent of software
development costs. Yet most people believe
that software is not well tested before it is
delivered. That contradiction is rooted in two
clear facts: First, testing software is a very
difficult proposition; and second, testing is
typically done without a clear methodology.
A widely-accepted in the industry -- and
an integral assumption in the Rational Unified
Process® (RUP®) -- is that it is better to start
testing as early in the software development
process as possible. Delaying the start of testing activities until all
development is done is a high-risk way to proceed. If significant bugs are
found at that stage (and they usually are), then schedules often slip.
Haphazard methods of designing, organizing, and implementing testing
activities and artifacts also frequently lead to less-than-adequate test
coverage. Having a straightforward plan for how testing is done can help
increase coverage, efficiency, and ultimately software quality.
In this article, we will discuss how using use cases to generate test cases
can help launch the testing process early in the development lifecycle and
also help with testing methodology.
In a software development project, use cases define system software
requirements. Use case development begins early on, so real use cases for
key product functionality are available in early iterations. According to the
RUP, a use case "…fully describes a sequence of actions performed by a
system to provide an observable result of value to a person or another
system using the product under development." Use cases tell the
customer what to expect, the developer what to code, the technical writer
what to document, and the tester what to test.
For software testing -- which consists of many interrelated tasks, each