2. 10.2.1 Systems Development
• Systems development is a problem-solving
process of investigating a situation; designing a
system solution to improve the situation;
acquiring the human, financial, and
technological resources to implement the
solution; and finally evaluating the success of the
solution.
• After a steering committee determines that a proposed
project is desirable, a project team of end users and
systems analysts is formed to develop the
system. An end user is a person who will use the
information system or the information it
provides. A systems analyst is the IT
professional who develops the system.
3. 10.2.2 The Systems Development
Life Cycle
• An information system has a systems
development life cycle (SDLC)—a
sequence of steps or phases it passes
through between the time the system is
conceived and the time it is phased out.
The phases of the systems life cycle
include: investigation, analysis, design,
development, implementation,
maintenance, and retirement.
4. Investigation
• System investigation involves defining the problem—
identifying the information needs of the organization,
examining the current system, determining how well it
meets the needs of the organization, and studying the
feasibility of changing or replacing the current system.
• After completing the initial investigation of the problem,
a systems analyst produces a feasibility study to help
management decide whether to continue with the system
analysis. Types of feasibility are:
• Technical.
• Economic.
• Operational.
• Organizational.
5. Analysis
• During the analysis phase, the systems analyst
gathers documents, interviews users of the current
system (if one exists), observes the system in action,
and generally gathers and analyses data to help
understand the current system and identify new
requirements. The systems analyst identifies the
requirements related to each subsystem of the
proposed system:
• Input/output requirements.
• Processing requirements.
• Storage requirements.
• Control requirements.
6. Design
• The investigation phase focuses on why, the analysis phase
focuses on what, and the design phase focuses on how. The
systems analyst considers important how-to questions in
three categories:
• User interface design.
• Database design.
• Process design.
• In many cases, the design phase produces a prototype
system—a limited working system or subsystem to
give the users and management an idea of how the
completed system will work. With prototyping, the
systems analyst can modify the prototype until it
meets the needs and expectations of the organization.
7. Development
• After the design is completed, the actual system
development can begin. A large part of the
development schedule is devoted to testing the
system. Members of the system development
team perform early testing to locate and
eliminate bugs. This initial testing is known as
alpha testing. Later, potential users who
are willing to work with almost-finished
software perform public beta testing and
report bugs to the developers.
8. Implementation
• When the testing is completed and known bugs have
been eradicated, the new system is ready to replace
the old one. In some cases, the new system is run in
parallel with the old system until the analyst is
confident that the new system is stable and reliable.
• The systems analyst can choose one of four
approaches for converting to the new system:
• Direct cutover.
• Parallel systems approach.
• Phase-in approach.
• Pilot approach.
9. Maintenance
• The maintenance phase involves evaluating,
repairing, and enhancing the system. For large
custom systems, maintenance involves a
continual process of evaluating and adjusting the
system to meet organizational needs. In either
case, maintenance usually lasts throughout the
lifetime of the system.
10. Retirement
• At some point in the life of a system, ongoing
maintenance isn’t enough. Because of changes in
organizational needs, user expectations,
available technology, and other factors, the
system no longer meets the needs of the users or
the organization. At that point, it’s time to phase
it out in favour of a newer system and begin
another round of the system life cycle.
