Information Systems in the Organization Instructor: Sanchita Mal-Sarkar Course: IST 221

What is an Information System? An information system contains information about an organization and its surrounding environment Environment Suppliers Customers Organization Information System Input Processing Output Feedback The important activities - input, processing, and output. Feedback is output returned to appropriate people or activities in the organization to evaluate and refine the input.

Information Systems IS is a collection of interrelated components that - collect (retrieve), process, store, and distribute information to support decision making and control in an organization. - also help managers and workers analyze problems, visualize complex subjects, and create new products. Three major activities: input, processing, output. Input => collects raw data from the organization/ external environment. Processing => converts this raw input into meaningful form. Output => transfer the processed information to the people/activities. Feedback => output that is returned to appropriate members of the organization to help them evaluate/correct the input stage.

Why Information Systems ? Earlier information itself was not considered an important asset for the firm. The management process was considered a face-to-face, personal art, not a global coordination process. However, today’s managers have to understand information systems because most organizations need information systems to survive and prosper. Three worldwide changes have altered the environment of business. 1. The emergence and strengthening of global economy 2. The transformation of industrial economies and societies into knowledge- and information-based service economies. 3. The transformation of the business enterprise

Why Information Systems ? 1. The emergence and strengthening of global economy A growing percentage of American economy- and other advanced industrial economies in Europe and Asia - depends on imports and exports. The success of a firm today depends on its ability to operate globally. Because of global communication and management systems, customers now can - shop in a worldwide marketplace. - obtain price and quality information reliably, 24 hours a day. - compare quality and price all over the world market.

Why Information Systems ? 2. The transformation of industrial economies and societies into knowledge- and information-based service economies. From the growth curve of the information economy it is clear that - the United States has experienced a steady decline in the number of farm workers and blue-collar workers who are employed in factories. - However, the country is experiencing a rise in the number of white-collar workers who produce economic value using knowledge and information.

Why Information Systems ? 3. The transformation of the business enterprise: The traditional business firm was a - hierarchical and centralized. structured arrangement of specialists. - Specialists relies on a fixed set of standard operating procedures to deliver product. - Traditional manager relies on formal plans, a rigid division of labor, formal rules The new business firm is - less hierarchical, decentralized, flexible arrangement of generalists . - New manager relies on informal commitments and networks to establish goals rather than formal planning.

Computer-based Information System Formal System based on accepted and fixed definitions of data and procedures (operating with predefined rules). Formal system Manual IS => use paper and pencil technology. Computer-bases IS => An information system that is based on computer hardware and software technology for processing and disseminating information. Computer-based manual

Computer An electronic machine that accepts input, processes data, stores data, and produces output. Data can be numbers, text, images, graphics, and sound, etc. Computer program is a set of instructions. Without it computer is useless. Programming languages allow us to write these instructions (e.g. C, C++, Java, etc).

Computer system A computer system consists of a computer, peripheral devices, and software. The computer itself can take care of the processing function, but it needs additional components, called peripherals, to accomplish its input, output and storage functions. Example of an internal peripheral device is hard disk drive.

Computer Hardware Hardware is the physical component of a computer. Hardware is the equipment used to perform the necessary computations. Examples: Main memory (RAM, ROM), secondary memory (hard disk drive, floppy disk drive), CPU, input devices (keyboard and mouse), and output devices (monitor and printer).

Hardware Components of a Computer System Central Processing Unit (CPU) Arithmetic-Logic Unit Control Unit Input Devices Secondary Storage Magnetic disk Optical disk Magnetic tape Keyboard Computer mouse Touch screen Source data automation Buses Output Devices Printers Video display terminals Plotters Audio output Communications Devices Primary Storage

Central Processing Unit (CPU) Coordinating all computer operations. Performs arithmetic and logical operations on data. To process a program stored in main memory, - CPU retrieves each instruction in sequence. - Interprets the instruction to determine what should be done. - Retrieves any data needed to carry out that instruction - Then CPU performs the actual manipulation. CPU’s current instruction and data values are stored temporarily inside the CPU in special high-speed memory locations called registers.

Central Processing Unit (CPU) The CPU consists of a control unit and an arithmetic-logic unit. Three kind of buses link the CPU, primary storage, and other devices in the computer systems. The data bus moves data to and from primary storage. The address bus transmits signals for locating a given address in primary storage. The control bus transmits signals specifying whether to read or write data to or from a given primary storage address, input device, or output device.

Data Bus, Address Bus, and Control Bus Central Processing Unit (CPU) Primary Storage 1 T U # 8 Arithmetic-Logic Unit 24 + 12 = 36 12 < 24 Control Unit Data Bus Address Bus Control Bus Output Devices Secondary Storage Input Devices

Computer Software Software consists of the computer programs that allow us to solve problems by providing sets of instructions. Examples: DOS, Windows, Mac. Office family, Lotus, Netscape, Internet Explorer, Virus scans, tax programs, computer games, GUI - Graphical User Interface.

The major types of software System Software Operating Systems Schedules computer events Allocates computer resources Monitor events Application software System software Hardware Language translators Interpreters Compilers Users Application Software Programming languages Assembly language FORTRAN, BASIC, PL/1 PASCAL, C “4th generation “ languages Utility programs Routine operations (e.g. sort, list, print) Manage data (e.g. create files, merge files

Binary Representation of Data For information to flow through a computer system, it must be in form suitable for processing. All symbols, pictures, or words must be reduced to a string of binary digits. A binary digit is called a bit and it represents either a 0 or a 1. In the computer, the presence of an electronic or magnetic signal means “one” and its absence means “zero”. A string of 8 bits that computer stores as a unit is called a byte. Each byte is used to store a decimal number, a symbol, a character, or a part of a picture. By using binary number system a computer can express all numbers as group of zeroes and ones. There are two standard binary codes: EBCDIC (Extended Binary Coded Decimal Interchange Code) ASCII (American Standard Code for Information Interchange).

Bits and Bytes 1 or One bit 1 1 One byte for character A 1 or One bit 1 1 One byte for character A The Computer representation in ASCII for the name Alice is: 1 A 1 1 1 L 1 I 1 1 1 C 1 1 1 E

Data Communications Channel => The message needs some kind of medium to be transmitted. This medium is called channel. For example, telephone or coaxial cable, microwave signal, or optical fibers Protocol => The rules that establish an orderly transfer of data between the sender and the receiver are called protocols. Computer software and hardware establish these protocols at the beginning of the transmission, and both computers have to follow the protocols to ensure accurate transfer of data.

Data Communications The transmission of text, numeric, voice, or video data from one machine to another is called data communications. For example, Send an electronic mail to your friends around the globe. The four essential components of data communications are a sender, a receiver, a channel, and a protocol. Sender => The computer that originates the message is called the sender. Receiver => The computer at the message’s destination is called the receiver.

Networks One of the most important types of data communications in the business world is a network connection. A network connects one computer to another computers and peripheral devices to share data and resources. There is a number of network configurations. local area network (LAN) => computers and peripheral devices are located relatively close to each other, generally in the same building. Client/server networks =>Some networks have file servers (one or more computers) that act as the central storage location for programs and that provide mass storage for most of the data used on the network. A network with a file server is called a client/server networks.

Networks Peer-to-peer networks => When a network does not have a file server, all the computers essentially are equal, and programs and data are distributed among them. This is called a peer-to-peer network. Each computer that is part of the network must have a network interface card installed. This device creates a communication channel between the computer and the network. Network software is also essential to establish the communications protocols. Standalone computer => A microcomputer that is not connected to a network is called a standalone computer.

Telecommunications Allows us to send and receive data over telephone lines. A modem connects a computer to a telephone jack. At the sending site, modem converts the digital signal from a computer into analog (continuous wave) signals (sound waves) that can traverse ordinary phone lines (modulation). At the receiving site, a second modem converts the analog signals back into digital signals (demodulation).

Telecommunications

Internet The internet was originally developed for the government to connect the researchers around the world to share data. Today, the internet is the largest network in the world that connects millions of people in almost 200 countries. The use of internet: electronic mail => This is the capability to send a message from one user’s computer to another user’s computer where it is stored until the receiver opens it. Message passes through electronic links called gateways. World Wide Web (Web) => Web is a huge database of information that is stored on the network servers in places that allow public access. The information is stored as text files called web pages.

Internet Hyperlinks => a place on a computer screen that is programmed to connect to a particular file on the same network server, or on a network v=server on the other side of the globe. Web browsing => communication software that help us navigate the WWW is called web browsing software or web browser.