INTRODUCTION TO INFORMATION SYSTEMS
What is System??
• A system;
• is a set of interrelated components
• with a clearly defined boundary
• working together to achieve a common set of objectives.
• These components are;
• connected (communicates)
• have independent functionalities.
• Systems have inputs, processing mechanisms, outputs, and feedback
ELEMENTS OF A SYSTEM
• Data can be defined as a representation of facts, concepts or instructions in a formalized manner which should be suitable for communication, interpretation, or processing by human or electronic machine.
• Data is any set of characters that has been gathered and translated for some purpose, usually analysis.
• Data can exist in a variety of forms;
as numbers or text on pieces of paper, as bits and bytes stored in electronic memory, or as facts stored in a person's mind.
TYPES OF DATA
• Student Data on Admission Forms: When students get admission in a college. They fill admission form. This form contains raw facts (data of student) like name, father’s name, address of student etc.
• Data of Citizens: During survey, data of all citizens is collected.
• Survey Data: Different companies collect data by survey to know the opinion of people about their product.
• Students Examination data: In examination data about obtained marks of different subjects for all students is collected.
INFORMATION
• Information is described as the data which is processed, organised, specific and structured, which is presented in the given setting.
• Information is a collection of facts organized in such a way that they have additional value beyond the value of the facts themselves.
• It assigns meaning and improves the reliability of the data, thus ensuring understandability and reduces uncertainty.
• When the data is transformed into information, it is free from unnecessary details or immaterial things, which has some value to the researcher.
EXAMPLES OF INFORMATION
• Census Report: Census data is used to get report/information about total population of a country and literacy rate etc.
• Survey Reports and Results: Survey data is summarized into reports/information to present to management of the company.
• Result Cards of Individual Students: In examination system collected data (obtained marks in each subject) is processed to get total obtained marks of a student. Total obtained marks are Information. It is also used to prepare result card of a student.
• Merit List: After collecting admission forms from candidates, merit is calculated on the basis of obtained marks of each candidate. Normally, percentage of marks obtained is calculated for each candidate.
Now all the candidates names are arranged in descending order by percentage. This makes a merit list.
DATA VS. INFORMATION
THE VALUE OF INFORMATION
• Value of information is directly linked to how it helps decision makers achieve their organization’s goals.
• For example, value of information might be measured in:
• Time required to make a decision
• Increased profits to company
WHAT IS AN INFORMATION SYSTEM?
An information system (IS) is a set of interrelated elements or components that collect (input), manipulate (process) and store, and disseminate (output) information and provide a feedback mechanism to meet an objective.
COMPONENTS OF AN INFORMATION SYSTEM
• Input
• Processing
• Output
• Feedback
COMPONENTS OF AN IS
INPUT
• Input is the activity of gathering and capturing raw data that should be processed.
• Input can be manual or automated.
E.g. Manual- Data entry using keyboard
Automated – Enter MCQ answers using Optical Mark Readers (OMRs)
• Input can take a variety of forms, from commands you enter from the keyboard or from another computer or device.
• Accurate input is critical.
PROCESSING
• Processing means converting or transforming input data into useful outputs by making calculations, comparisons and arranging raw data.
• Sometimes, processing involves storing data for future use.
• Processing can involve making calculations, comparing data and taking alternative actions, and storing data for future use.
• Processing data into useful information is critical in business settings. This is a critical part in an information system.
OUTPUT
• In information systems, output involves producing useful information using results of the processing activity, usually in the form of documents and reports.
E.g. pay slip of each employee, sales report
• In some cases, output from one system can become input for another. For example: output from a system that processes sales orders can be used as input to a customer billing system.
FEEDBACK
• Feedback is a kind of output that is used to make changes to input or processing activities.
• For example, errors or problems might make it necessary to correct input data or change to the logic of the process.
• Feedback is also a very important component for managers and decision makers.
MANUAL AND COMPUTERIZED INFORMATION SYSTEMS
• An information system can be:
• Manual
• Computerized
• Manual systems still widely used E.g. some investment analysts draw charts and trend lines manually to assist them in making investment decisions.
• Computerized systems
• E.g. the above charts and trend lines can be drawn by a computer
COMPUTER BASED INFORMATION SYSTEM (CBIS)
A computer-based information system (CBIS) is a single set of hardware, software, databases, telecommunications, people, and procedures that are configured to collect, manipulate, store, and process data into information.
•A CBIS is composed of…
1. HARDWARE
2. SOFTWARE
3. DATABASES
4. TELECOMMUNICATIONS AND NETWORKS
5. PROCEDURES 6. PEOPLE
1. HARDWARE
• Hardware consists of the physical components of a computer that perform the input, processing, storage, and output activities of the computer.
• Other than the main computer system unit (including the CPU and primary memory), all other hardware devices are known as peripheral devices (input, output, storage)
• Computer hardware devices are grouped under 4 major categories: 1. Input devices
2. Processing devices
3. Output devices
4. Storage device
2. SOFTWARE
• Software consists of the computer programs that govern the operations of the computer.
• CPU needs software to control its functions as well as to process the input data.
• Gives the computer the power to act as an intelligent machine.
• Without software, computers are dead hardware
• Software is normally classified into two components called:
i. Application Software
ii. System Software
i. Application Software
• Application Software is a set of programs designed to carry out operations for a specified purpose or task.
• Examples: Packaged application (e.g. MS Office, spread sheets, etc) and database management systems or developed according to user requirements (bespoke) , accounting applications, web browser, photo editor, etc.
ii. System Software
• Application software cannot run without having system software. • Hardware devices together with system software provide the infrastructure to run/execute application software.
• System software communicates with hardware devices to coordinate activities.
• System software includes the operating system and all the utilities that enable the computer to function.
• Ex: Operating systems , are the main examples for system software - Microsoft Windows, Linux, Unix, Mac OSX, DOS, etc.
3. DATABASES
• A database is an organized collection of data and information in an organization.
• A collection of information organized in such a way that a computer program can quickly select desired pieces of data.
• An organization’s database can contain facts and information on customers, employees, inventory, competitors’ sales, online purchases, and much more.
• Special application software is used to create databases. These software is known as Database Management Systems (DBMS).
4. TELECOMMUNICATIONS AND NETWORKS
Telecommunications
• Telecommunications is the electronic transmission of signals (i.e. data, voice, messages) for communications which enables organizations to link computer systems and to carry out their processes and tasks through effective networks.
Networks
• Used to connect computers and computer equipment in a building, around the country, across the world, to enable electronic communications.
• There are many types of computer networks, including:
• local-area networks (LANs) : The computers are geographically close together (that is, in the same building).
• wide-area networks (WANs) : The computers are further apart and are connected by telephone lines or radio waves.
5. PROCEDURES
• A CBIS must be used according to some procedures to utilize it to achieve an objective.
• Procedures include the strategies, policies, methods, and rules for using the CBIS, including the operation, maintenance, and security of the computer.
• For example,
• Some procedures describe when each program should be run.
• Others describe who can access facts in the database or what to do if a disaster, such as a fire, earthquake, or hurricane, renders the CBIS unusable.
• Policies
• Procedures may include policies of the organization.
E.g. A policy may describe which group of users have access to a certain database.
• Methods
• Methods describe the steps to be followed to perform a certain task.
E.g. When you want to take a print out of your transactions in your savings account from the banking Information System, you must know the method to do it.
6. PEOPLE
• People who use an information system or who produced information by a CBIS.
• Users are people who work with information systems to get results.
• People can be the most important element in most computer-based information systems.
• They make the difference between success and failure for most organizations.
No comments:
Post a Comment