Information Technology Reference
In-Depth Information
reduces paper-based documentation, automates program
source code generation, and facilitates user participation in
development activities. RAD can use newer programming
techniques, such as agile development or extreme program-
ming. RAD makes extensive use of the joint application
development (JAD) process to gather data and perform
requirements analysis. JAD involves group meetings in which
users, stakeholders, and IS professionals work together to
analyze existing systems, propose possible solutions, and
define the requirements for a new or modified system.
The term end-user systems development describes any
systems development project in which the primary effort is
undertaken by a combination of business managers and
users.
Many companies hire an outside consulting firm that spe-
cializes in systems development to take over some or all of its
systems development activities. This approach is called out-
sourcing. Reasons for outsourcing include companies' belief
that they can cut costs, achieve a competitive advantage with-
out having the necessary IS personnel in-house, obtain state-
of-the-art technology, increase their technological flexibility,
and proceed with development despite downsizing. Many
companies offer outsourcing services, including computer
vendors and specialized consulting companies.
A number of factors affect systems development success.
The degree of change introduced by the project, continuous
improvement and reengineering, the use of quality programs
and standards, organizational experience with systems devel-
opment, the use of project management tools, and the use of
CASE tools and the objected-oriented approach are all factors
that affect the success of a project. The greater the amount
of change a system will endure, the greater the degree of risk
and often the amount of reward. Continuous improvement
projects do not require significant business process or IS
changes, while reengineering involves fundamental changes
in how the organization conducts business and completes
tasks. Successful systems development projects often involve
such factors as support from top management, strong user
involvement, use of a proven methodology, clear project goals
and objectives, concentration on key problems and straight-
forward designs, staying on schedule and within budget, good
user training, and solid review and maintenance programs.
Quality standards, such as ISO 9001, can also be used during
the systems development process.
The use of automated project management tools enables
detailed development, tracking, and control of the project
schedule. Effective use of a quality assurance process
enables the project manager to deliver a high-quality system
and to make intelligent trade-offs among cost, schedule, and
quality. CASE tools automate many of the systems develop-
ment tasks, thus reducing an analyst's time and effort while
ensuring good documentation. Object-oriented systems
development can also be an important success factor. With
the object-oriented systems development (OOSD) approach,
a project can be broken down into a group of objects that
interact. Instead of requiring thousands or millions of lines
of detailed computer instructions or code, the systems
development project might require a few dozen or maybe a
hundred objects.
Principle
Systems development starts with investigation and
analysis of existing systems.
In most organizations, a systems request form initiates the
investigation process. Participants in systems investigation
can include stakeholders, users, managers, employees, ana-
lysts, and programmers. The systems investigation is
designed to assess the feasibility of implementing solutions
for business problems, including technical, economic, legal,
operational, and schedule feasibility. Net present value anal-
ysis is often used to help determine a project's economic
feasibility. An investigation team follows up on the request and
performs a feasibility analysis that addresses technical, eco-
nomic, legal, operational, and schedule feasibility.
If the project under investigation is feasible, major goals
are set for the system's development, including performance,
cost, managerial goals, and procedural goals. Many compa-
nies choose a popular methodology so that new IS employees,
outside specialists, and vendors will be familiar with the sys-
tems development tasks set forth in the approach. A systems
development methodology must be selected. Object-oriented
systems investigation is being used to a greater extent
today. The use case diagram is part of the Unified Modeling
Language that is used to document object-oriented systems
development. As a final step in the investigation process, a
systems investigation report should be prepared to document
relevant findings.
Systems analysis is the examination of existing systems,
which begins after a team receives approval for further study
from management. Additional study of a selected system
allows those involved to further understand the system's
weaknesses and potential areas for improvement. An analysis
team is assembled to collect and analyze data on the existing
system.
Data collection methods include observation, interviews,
questionnaires, and statistical sampling. Data analysis
manipulates the collected data to provide information. The
analysis includes grid charts, application flowcharts, and
CASE tools. The overall purpose of requirements analysis is
to determine user and organizational needs.
Data analysis and modeling is used to model organiza-
tional objects and associations using text and graphical dia-
grams. It is most often accomplished through the use of
entity-relationship (ER) diagrams. Activity modeling often
employs data-flow diagrams (DFDs), which model objects,
associations, and activities by describing how data can flow
between and around various objects. DFDs use symbols for
data flows, processing, entities, and data stores. Application
flowcharts, grid charts, and CASE tools are also used during
systems analysis.
Requirements analysis determines the needs of users,
stakeholders, and the organization in general. Asking directly,
