The Four Stages of Processing
The Four Stages of Processing
All information systems operate in the same basic fashion whether they include a computer or not. However, the computer provides a convenient means to execute the four main operations of an information system:
• Entering data into the IS
(input) .
• Changing and manipulating the data in the IS (data processing) . • Getting information out of the IS
(output) .
• Storing data and information (storage) .
A computer-based IS also uses a logical process to decide which data to capture and how to process it. This process will be discussed later.
Input The first step in producing information is collecting and introducing data, known as input, into the IS. Most data an organization uses as input to its ISs are generated and collected within the organization. These data elements result from transactions undertaken in the course of doing business. A transaction is a business event: a sale, a purchase, a payment, the hiring of a new employee, and the like. These transactions can be recorded on paper and later entered into a
computer system; directly recorded through terminals of a transaction processing system
(TPS) , such as a point-of-sale (POS) machine; or captured online when someone transacts through the Web. A TPS is any system that records transactions. Often, the same system also processes the transactions, summarizing and routing information to other systems; therefore, these systems are transaction processing systems, not just transaction recording systems.
Input devices (devices used to enter data into an IS) include the keyboard (currently the most widely used), infrared devices that sense bar codes, voice recognition systems, and touch screens. Chapter 4, “Business Hardware,” describes these and other means to input data. The trend has been to decrease the time and effort of input by using devices that allow scanning or auditory data entry.
Processing The computer’s greatest contribution to ISs is efficient data processing. The computer’s speed and accuracy enable organizations to process millions of pieces of data in several seconds. For example, managers of a national retail chain can receive up-to-date information on inventory levels of every item the chain carries and then order accordingly; in the past, obtaining such information would take days. The huge gains in the speed and affordability of computing have made information the essential ingredient for an organization’s success.
PART 1 THE INFORMATION AGE PART 1 THE INFORMATION AGE
Storage One of the greatest benefits of using IT is the ability to store vast amounts of data and information. Technically, storing a library of millions of volumes on magnetic or optical storage media is feasible. Publishers, libraries, and governments have done that. For example, close to
8 million patents registered in the United States are stored on storage devices accessible through the Web.
Computer Equipment for Information Systems
To support the four data processing functions, different types of technologies are used. Figure 1.6 illustrates the five basic components of the computer system within an IS:
• Input devices introduce data into the IS. • The computer processes data through the IS. • Output devices display information. • Storage devices store data and information. • Networking devices and communications lines transfer data and information over various
distances.
FIGURE 1.6
Input, process, output, storage, and networking devices
Process Device
Internet
(Computer)
Output Devices Input Devices
Storage Devices
In addition to communication that takes place between computer components, communi- cation occurs between computers over great distances (called telecommunications ). Commu- nications technology lets users access data and other electronic resources of many computers, all connected in a network. This way, the capabilities of a single computer might be augmented with the power of an entire network.
Chapter 1 Business Information Systems: An Overview □ 17
Different types of information systems serve different functions —for particular types of organi- zations, functions within organizations, business needs, and management levels of an organization. Business enterprises differ in their objectives, structure, interests, and approaches. However, ISs can be generally categorized based on the level of a system’s complexity and the type of functions it serves. ISs in business range from the basic transaction processing system that
records events such as sales to sophisticated expert systems, which provide advice and reduce the need for the expensive services of a human expert. In recent years the capabilities of many applications have been combined and merged. It is less likely that you will find any of the following applications as stand-alone systems with a single capability. Managers and other professionals plan, control, and make decisions. As long as a system supports one or more of these activities, it may be referred to as a management information system (MIS) .