Business Information System
Information System – A set of interrelated components that collect, retrieve, process, store and distribute information for the purpose of facilitating planning, control, coordination, analysis and decision making in organisations. Input – the capture or collection of raw data resources from within an organisation or from its external environment. Processing – The conversion of raw input into a more appropriate and useful form. Output – The transfer of processed information to the people or activities that will use it. Feedback – Output that is returned to appropriate members of the organisation to help them refine or correct the input phase. Formal Systems – Information Systems that rely on mutually accepted and relatively fixed definitions of data and procedures for collecting, storing, processing and distributing information. Manual Systems – An information system that uses only paper and pencil technology and does not rely on computers. Computer Hardware – the physical equipment used for the input, processing and output work in an information system.
Computer Software – Preprogrammed instructions that coordinate the work of computer hardware components to perform the processes required by each information system. Storage Technology – physical media for storing data and the software governing the organisation of data on
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TOPIC 1 – Introduction to information systems Define an information system A collection of people, equipment and procedures that need to be carried out in order to achieve some goal. Basic components of an information system Input, processing, output and feedback How do knowledge, information and data differ? Data – raw facts that can be shaped and formed to create information. Information – data that have been shaped by humans into a meaningful and useful form. Knowledge – the stock of conceptual tools and categories used by humans to create, collect, store and share information. Compare and contrast information systems literacy with computer literacy Computer literacy – knowledge about the use of information technology, including hardware, software, telecommunications and information storage techniques. Information Systems literacy – knowledge and hands-on facility with information technologies, a broadly based understanding of organisations and individuals from a behavioral perspective and a similar understanding of how to analyse and solve problems.
Aims of business Make a profit for its owners and for shareholders Obey laws and regulations Provide a service to its customers Provide a safe and workable environment for its employees Ensure longevity of the business Four major functions of business Production, sales and marketing, human resources, finance and accounting All functions rely on information to operate successfully Topic 2 – How business firms use information Definition of a business organisation A complex, formal organisation whose goal is to produce a product or service for a profit. The major functions performed by business Manufacturing and production, sales and marketing, finance and accounting, and human resource activities The role of information systems within business organisations To deal with internal organisation problems and to ensure their survival in a changing external environment Examples of basic business systems Manufacturing and production systems – the division of a business organisation that produces the firms goods or services.
Typical production process, inbound logistics, production, outbound logistics. A common example of a manufacturing/production system is the bill-of-materials system, which helps firms keep track of products that require a particular part. A bill-of-materials system is useful for determining costs, coordinating orders and managing inventory. Sales and marketing systems – the division of a business organisation that sells the firm’s product or service Three steps involved in sales and marketing: – identifying and creating a market – developing it – maintaining it. A sales information system can capture sales data for the computer at the moment the sale takes place for further analysis. Topic 3 – Computer hardware CPU – central processing unit RAM – random access memory ROM – read only memory The components of a computer and how they work CPU – a complex set of electronic circuitry that executes stored program instructions. In small computers the CPU will be fitted onto a single logic chip while in larger systems it might be constructed from hundreds of separate chips containing specialised circuits. RAM – can be described as read-write chips.
A CPU can read the data stored in a RAM chip as well as write new data to replace what is there. RAM is usually volatile i.e. the data is lost once the power is shut off. ROM – was developed to address the problem of votatility. The bits stored in ROM are permanently burnt into the chip, ROM is not volatile. A ROM chip contains the microcode or instructions that can be permanently recorded into the memory and this is usually done as a step in the computers manufacture. The more RAM there is in your computer the larger and more powerful the programs you can run. The binary system. Bits are put together in a group called a byte which represents one character of data. Kilobyte – a measure of computer storage capacity, approximately 1,000 bytes Megabyte – approximately 1 million bytes Gigabyte – approximately 1 billion bytes Terabyte – approximately 1 trillion bytes How computers actually work The CPU interacts with ‘data’ in primary memory. The ‘data’ in primary memory may be either data in the usual sense of the word, or it may be stored computer instructions.
No matter what is held in primary memory though, it is stored in bits, zeroes and ones. At its base level, a computer is a device that manipulates switches. It turns them on and off, very quickly. Computers become useful when we use combinations of the switches to represent some real world problem. Some sort of agreed upon combination of bits or bit code is used to represent whatever it is that we wish to process. There are many codes used in computing. We need codes to represent sound and graphics besides alphabetic characters and numbers. How the major input and output technologies work The input process – process of firstly transferring whatever it is that we wish to store into a bit pattern that the computer can manipulate, and secondly, actually getting that bit pattern into the computer. Mouse, touch screen, bar code, pen-based input, scanner, voice input devices, sensors, keyboard, audio input, video input.
The output process – transferring bit combinations out of computer storage and then decoding them ad presenting them to the world outside of the computer in a useful form. Printer, plotter, audio output. Storage technology Secondary storage – the relatively long term storage outside of the CPU Magnetic tape – a secondary storage medium in which data are stored by means of magnetized and unmagnetized spots on tape. Magnetic disk/floppy disk – the most popular secondary storage, data stored by means of magnetized spots on hard or floppy disks. Hard disk – a type of magnetic disk resembling a thin platter, where relatively large quantities of data can be stored and data can be rapidly accessed. Optical disk – where data are recorded and read by laser beams rather than by magnetic means, can store much more data than magnetic disks. WORM – Write once read many.
CD-ROM – compact disk- read only memory Multimedia, network computers, and future information technology trends Multimedia – the integration of two or more types of media such as text, graphics, sound, full-motion video, or animation into a computer-based application. Network computer – a pared-down desktop computer that does not store software programs or data permanently, obtaining them when they are needed over a network. Classification of computers Supercomputers Very powerful, special purpose systems often incorporating ‘parallel processors’ to increase computation through output. Mainframes Large and powerful general-purpose systems used where vast amounts of data have to be processed quickly. Mini computers Less powerful and cheaper than mainframes but functionally similar. Micro computers (Personal computers) Designed for single user, general-purpose usage, although PC’s can often be used in similar ways to mini computers. Topic 4 – Information systems software Software – instructions that tell the computer what to do, a set of programs, procedures, routines and documents associated with the operation of a computer system.
The roles systems software and applications software play in information’s systems Software is divided into two broad categories; systems software and applications software. Systems software is machine specific software that ensures the orderly running of the computer and provides various services that may be utilized by other software and users. Most important component is the operating system. Operating system coordinates and enables all other software and hardware activity, examples DOS – command line interface e.g. c:dir*.doc, Windows – graphical interface, UNIX. Applications software is software that allows the computer to perform useful tasks. Word processing, spreadsheets, payroll etc. The generations of computer software 1. Machine language 2. Symbolic languages such as assembly language 3. High-level languages such as FORTRAN and COBOL 4. Fourth generation languages which are less procedural and closer to natural language than earlier generations. How the operating system functions Acts as the chief manager of the computer system, allocating, scheduling, and assigning system resources and monitoring the use of the computer.
Select appropriate software for business applications Word processing, spreadsheets, data management software, integrated software packages such as office, Web browsers. Topic 5 – Organising information; files and databases Describe the role of databases in modern information systems Allows organisations to maintain data that that is organised and structured that can be accessed easily. Definition of the concept of information resource management/Database management system (?) Software that serves as an interface between a common database and various application programs; it permits data to be stored in one place and to be made available to different applications. The hierarchy of data present in computer systems Database File – collection of related records, customers Record – the data for one entity in the file – customer Charlie brown Field – one item of data in a record – name, address or balance owing Byte – a letter, digit, symbol Bit Previous techniques in storing information in computers Traditional file environment – the storage of data so that each application has its own separate data file or files and software programs.
Either a sequential file organisation or a random file organisation. Different techniques of processing using files Direct file access involves a mathematical operation called a randomizing algorithm. Online transaction processing – used for airline reservations and other applications in which information must be processed immediately Problems with traditional file approaches namely those of data redundancy and program/data dependence Data redundancy – the presence of duplicate data in multiple data files Program/data dependence – the close relationship between data stored in files and the specific software programs required to update and maintain those files, whereby any change in data format or structure requires a change in all the programs that access the data.
The concept, components and advantages of database management systems The true database approach to organising information stores data physically in only one location and uses special database management software so that this common pool of data can be shared by many different applications. Three components: Data definition language – used to define the structure of the database Data manipulation language – used to query and change data Data dictionary – used to store information about the structure of data Advantages are: – independence of data from application programs – reduction of data redundancy and inconsistency – elimination of data confusion – consolidation of data management – ease of information access and use Three different database systems and their models The hierarchical model – top-down manner, each record is broken down into multilevel segments, one to many, parent to child relationship The network model – depicts a many to many relationship The relational model – two-dimensional tables called relations, a data element in any one table can be related to any piece of data in another table as long as both tables share a common data element.
The steps involved in the logical (or conceptual) design steps in database development 1. Identifying the functions the solution must perform 2. Identifying the pieces of data required by each function 3. Grouping the data elements in the manner that most easily and efficiently delivers the solution Occasions where files are still of more use in development than databases Personal computers, very small organisations. The need for distributed databases Distributed database – a complete database or portions of a database that are maintained in more than one location. Three different techniques for the distribution of data Partitioned – subdivided so that each location has only the portion of the database that serves its local needs. Replicated – a central database that is duplicated at all other locations Online Several leading edge technologies in databases Object-oriented database – stores data and processing instructions as objects that can be automatically retrieved and stored. Hypermedia database – organised to store text, graphics, audio or video as nodes that can be linked in any pattern established by the user. Data warehouse – consolidates data from various operational systems for use in reporting and analysis.