Information Technology Workbook
9 System development
Two ways exist to acquire the software needed to support
a business. Both begin by developing an understanding
of the processes to be automated in an effort known as systems
analysis. Business processes are examined and
documented, and interfaces between the outside
world and the organization identified. Then a choice is made:
is there any software available in the marketplace that provides
a close enough fit to meet requirements or must software be developed
to suit? In both cases a
system development methodology (SDM) is used.
The system development life cycle (SDLC) is a
common SDM. This "waterfall model"
assumes that planning, analysis, design, development
(programming), testing, implementation and maintenance can
follow linearly in stages and uses
data flow
diagramming (DFD) to map information flow.
Other SDMs include prototyping,
joint application development (JAD), and rapid application
development (RAD) with computer-aided
software engineering (CASE) tools to generate
program code and documentation. When purchases
are planned a
request for proposal (RFP) is written
describing needs and is sent to prospective
vendors. Vendors submit proposals and in some
cases a "proof of concept" demonstration that may
lead to a contract.
9.1 Why do we need a system development methodology (SDM)?
9.2 "Traditional" method: the waterfall and its problems
9.3 Definitions of some system analysis terms
9.4 Joint Application Development (JAD)
9.5 Rapid Application Development (RAD)
9.6 Newer system and software development models
9.7 Purchasing systems or outsourcing systems development
9.8 End user development and software testing
Click here to return to the top of Chapter 9