330 Part III • Acquiring Information Systems
FIGURE 8.1 An Example of Poor DesignThis section provides some templates for analyzing,
describing, and redesigning systems. The systems
concepts we discuss are general ones, although we will use
many information systems examples.
What Is a System?
Asystemis a set of interrelated components that must
work together to achieve some common purpose. This is
simply said but more difficult to apply. An example of
what happens when system components do not work
together appears in Figure 8.1. This house has all the
components (e.g., rooms, doors, windows, plumbing,
electrical wiring) necessary for a functioning home, but the
components just do not fit together. For example, the
outside steps do not lead to a door. The lesson here is that
even when a given component is well-designed, simple,
and efficient to operate, the system will malfunction if the
components do not work together.
Further, a change in one component could affect
other components. For example, if the marketing group
(one component part of a business) sells more of some
product than expected, the production group (another
component) would have to special-order materials or pay
overtime to produce more than the planned amount. If the
interrelationships between these functions (components)
are not well managed, an unanticipated result might be a
rise in the costs of goods sold, leading to the company
actually losing money from increased sales.
Aninformation system (IS)can be defined in a
very broad way as the collection of IT, procedures, and
people responsible for the capture, movement, manage-
ment, and distribution of data and information. As with
other systems, it is crucial that the components of an IS
work well together. That is, the components must be
consistent, minimally redundant, complete, and well
connected with one another.Seven Key System Elements
Systems share the seven general elements; it is one or more
of these elements that change or are created when we
redesign or design a new (information) system. These seven
general system elements are briefly defined as follows: