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44 Chapter 2 • Systems Integration

IS Architectures
Today’s IS can be configured using a wide range of system architectures depending on the infor-
mation needs of the organization. The continuing rapid advances in computer and networking
technologies, as well as changing organizational dynamics, drive the emergence of new informa-
tion system models. Today’s Web-based model will evolve and morph as business models
change to meet the demands of customers and clients.
As with today’s Web-based systems, using a distributed architecture allows sharing of
applications and data resources between the client and the server computers. It combines features
from the centralized and decentralized architectures. In this configuration, personal computers
are connected via a network to a Web server that provides a window to an application and
database server(s), which could be a mainframe or another type of computer. The server usually
houses applications and data that are shared across the organization, whereas PCs store applica-
tions and data that do not require any sharing. This architecture provides a highly integrated
approach for updating and sharing of data in real time, hence minimal duplication of effort and
increased data consistency. Although they are very flexible and scalable, there are some
drawbacks. The architecture is very complex and requires careful planning and design. In addi-
tion, it requires a highly trained IT support staff to manage and coordinate a wide variety of
applications, operating systems, and hardware.

IS Functionalization

In addition to serving the different management levels, IS also supports such major business
functions as manufacturing, marketing, accounting, finance, and HR. Each functional area
similarly has different information needs and report requirements. For example, an HR IS will
provide information on employee payroll and benefits, whereas a manufacturing IS will provide
reports on job shop schedules and parts inventory. To complicate these matters further, each
functional area in an organization has multiple levels of management, each requiring different

Net PC File
Device PC Modem 1 PC 2 Server

Server
Printer Printer
Printer PC

CENTRALIZED DECENTRALIZED

PC

File
PC
Server
Printer
DISTRIBUTED
FIGURE 2-5 Information Systems Architectures