programming-for-dummies

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Software Engineering Methods
Despite the rationale behind the waterfall method, it hasn’t consistently produced
large, reliable programs on schedule. The biggest flaw with the waterfall
method is its rigidity. If one phase gets stalled for any reason, the entire
project grinds to a halt. If programmers misinterpret the customer’s requirements
between two different steps (such as the analysis and design phase),
the error can continue down through each succeeding phase, resulting in a
final program that’s flawed (at best) or completely unusable (at worst).
Evolving a program with extreme programming
In response to the over-structured waterfall method, programmers have gone
to the opposite side with extreme programming (often abbreviated as XP).
The whole idea behind extreme programming (or agile programming) is to
recognize that all four phases (analysis, design, implementation, and testing)
are not distinct, isolated steps but integrated steps that flow back and forth
throughout the life of a project.
Phases
Instead of the analysis, design, implementation, and testing phases defined
by the waterfall method, extreme programming defines four different, mutually
overlapping phases:
✦ Coding
✦ Testing
✦ Listening
✦ Designing
Which approach is better? The answer: Both
and neither:
Although you may not want to be as regimented
and rigid as the waterfall model,
you may appreciate its structure and
emphasis on defining every phase before
moving on to the next step.
Extreme or waterfall?
If you’re the type of person who needs
more structure, extreme programming may
be too chaotic.
Whichever method — or combination of
methods — you choose, the ultimate goal of
any software engineering method is to provide
a systematic way to create large, reliable programs
on a consistent basis and as quickly as
possible.