Java Reference
In-Depth Information
A software project usually starts because a customer has a problem and is willing to
pay money to have it solved. The Department of Defense, the customer of many
programming projects, was an early proponent of a formal process for software
development. A formal process identifies and describes different phases and gives
guidelines for carrying out the phases and when to move from one phase to the next.
A formal process for software development describes phases of the development
process and gives guidelines for how to carry out the phases.
Many software engineers break the development process down into the following five
phases:
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Analysis
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Design
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Implementation
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Testing
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Deployment
In the analysis phase, you decide what the project is supposed to accomplish; you do
not think about how the program will accomplish its tasks. The output of the analysis
phase is a requirements document, which describes in complete detail what the
program will be able to do once it is completed. Part of this requirements document
can be a user manual that tells how the user will operate the program to derive the
promised benefits. Another part sets performance criteriaȌhow many inputs the
program must be able to handle in what time, or what its maximum memory and disk
storage requirements are.
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In the design phase, you develop a plan for how you will implement the system. You
discover the structures that underlie the problem to be solved. When you use
object-oriented design, you decide what classes you need and what their most
important methods are. The output of this phase is a description of the classes and
methods, with diagrams that show the relationships among the classes.
