Information Technology Reference
In-Depth Information
Several common systems development life cycles exist: traditional, prototyping, rapid
application development (RAD), and end-user development. In addition, companies can
outsource the systems development process. With some companies, these approaches are
formalized and documented so that systems developers have a well-defined process to follow;
other companies use less formalized approaches. Keep Figure 12.5 in mind as you are intro-
duced to alternative SDLCs in the next section.
The Traditional Systems Development Life Cycle
Traditional systems development efforts can range from a small project, such as purchasing
an inexpensive computer program, to a major undertaking. The steps of traditional systems
development might vary from one company to the next, but most approaches have five
common phases: investigation, analysis, design, implementation, and maintenance and re-
view (see Figure 12.6).
Figure 12.6
The Traditional Systems
Development Life Cycle
Sometimes, information learned in
a particular phase requires cycling
back to a previous phase.
SYSTEMS INVESTIGATION
Understand problem
SYSTEMS ANALYSIS
Understand solution
SYSTEMS DESIGN
Select and plan best solution
SYSTEMS IMPLEMENTATION
Place solution into effect
SYSTEMS MAINTENANCE
AND REVIEW
Evaluate results of solution
systems investigation
The systems development phase
during which problems and
opportunities are identified and
considered in light of the goals of the
business.
In the
systems investigation
phase, potential problems and opportunities are identified
and considered in light of the goals of the business. Systems investigation attempts to answer
the questions “What is the problem, and is it worth solving?” The primary result of this phase
is a defined development project for which business problems or opportunity statements
have been created, to which some organizational resources have been committed, and for
which systems analysis is recommended.
Systems analysis
attempts to answer the question
“What must the information system do to solve the problem?” This phase involves studying
existing systems and work processes to identify strengths, weaknesses, and opportunities for
improvement. The major outcome of systems analysis is a list of requirements and priorities.
Systems design
seeks to answer the question “How will the information system do what it
must do to obtain the problem solution?” The primary result of this phase is a technical
design that either describes the new system or describes how existing systems will be modified.
The system design details system outputs, inputs, and user interfaces; specifies hardware,
systems analysis
The systems development phase
that determines what the
information system must do to solve
the problem by studying existing
systems and work processes to
identify strengths, weaknesses, and
opportunities for improvement.
systems design
The systems development phase
that defines how the information
system will do what it must do to
obtain the problem solution.
