AIN1501 EXAM PACK.

AIN1501 EXAM PACK. AIN1501 - Accounting Information Systems In A Computer Environment. First order control system, second-order control system, third-order control system. NOTES Cybernetic control A system is defined as a set of interrelated components, with a clearly defined boundary, working together to achieve a common set of objectives by accepting inputs and producing outputs in an organized transformation process . Systems have three basic functions: • Input involves capturing and assembling elements that enter the system to be processed. For example, raw materials, energy, data, and human effort must be secured and organized for processing. • Processing involves transformation processes that convert input into output. Examples are manufacturing processes, the human breathing process, or mathematical calculations. • Output involves transferring elements that have been produced by a transformation process to their ultimate destination. For example, finished products, human services, and management information must be transmitted to their human users. A system with feedback and control functions is sometimes called a cybernetic system, that is, a self-monitoring, self-regulating system. • Feedback is data about the performance of a system. For example, data about sales performance are feedback to a sales manager. Data about the speed, altitude, attitude, and direction of an aircraft are feedback to the aircraft’s pilot or autopilot. • Control involves monitoring and evaluating feedback to determine whether a system is moving toward the achievement of its goal. The control function then makes the necessary adjustments to a system’s input and processing components to ensure that it produces proper output. 3.2 -The current and previous years’ financial results to determine the profitability of the organisation. _ Prediction of the organisation’s future performance _ Alternative strategies to reach the objective NOTES People require information for different reasons. Typical information required by top management to perform their strategic management function consists of: _ The current and previous years’ financial results to determine the profitability of the organisation. _ Prediction of the organisation’s future performance _ Alternative strategies to reach the objective _ The effect of the changing environment on the performance or future existence of the organisation. email: Tel : 9 Cell : 3 GR TUTORIALS 3.3 A system is a set of two or more components that serve a common purpose and interact to achieve a common goal. A system consists of subsystems or elements that perform specific functions supporting the larger system. Most business systems are open systems. NOTES Systems operate within their environment. Some systems have no effect on their environment and do not affect the environment within which they operate. A system that is isolated from its environment is called a closed system. An example would be an automatic washing machine, where the dirty clothes, washing powder and knowledge are the input and the processing stage of the washing cycle would be the selection of a suitable programme and the operating of the machine. The clean clothes are the output. An open system interacts with its environment. The environment affects it and it, in turn, affects its environment. Most business systems are open systems. QUESTION 4 4.1 THE CONTROL INIT ALU – ARITHMETIC LOGIC UNIT NOTES Central processing unit (CPU) The CPU is the component of a computer system that carries out the instructions of computer programs, and is the primary component of a computer. The CPU carries out the instructions of a program in sequence by performing the basic arithmetical, logical, and input/output operations of the system. The CPU is, effectively, the brain of the computer. A CPU consists of three components: . The arithmetic/logic unit (ALU), which performs mathematical calculations and logical operations . The control unit, which fetches program instructions, decodes them and directs the instructions in and out of the ALU, the registers, the primary and secondary storage, and the output devices . Registers (primary memory) are temporary high-speed storage areas used to hold program instructions before, during and after their execution by the CPU. 4.2 RAM, ROM, PROM/EEPROM. NOTES Primary memory Primary memory or main memory is also just called ``memory''. The CPU stores and retrieves information directly from and to the memory. This memory is accessed by the CPU, in a random manner, thus any location of this memory can be accessed by the CPU either to read information from it, or to store information on it. Two types of memory technology implement primary memory. The first is called random email: Tel : 9 Cell : 3 GR TUTORIALS access memory (RAM) and the other is read only memory (ROM). The CPU can write and read information from any primary memory location implemented using RAM. The other part of primary memory is implemented using ROM. The different types of primary memory are described in detail below: . RAM (random access memory): RAM is the main memory. Data can be written into RAM and be read from RAM. In contrast, ROM only permits you to read data. Generally, RAM is volatile, which means that it requires a steady flow of electricity to maintain its contents. As soon as the power is turned off, whatever data were in RAM, is lost. . ROM (read-only memory): Most computers contain read-only memory that holds instructions for starting up the computer. One cannot write data to ROM and ROMs are non-volatile. Non-volatile means that this type of memory does not require a steady flow of electricity to maintain its contents. The ROM will retain its contents even if the power is turned off. . PROM (programmable read-only memory): A PROM is a memory chip on which a program can be stored. Once a PROM has been used, the program cannot be erased or be used to store something else. PROMs are non-volatile. . EPROM (erasable programmable read-only memory): An EPROM is a type of PROM that can be erased by exposing it to ultraviolet light. EPROMs are non-volatile. . EEPROM (electrically erasable programmable read-only memory): An EEPROM is a type of PROM that can be erased by exposing it to an electrical charge. EEPROMs are non-volatile. 4.3 NOTES Computer systems: • Instrument that processes data into information Computerised information systems are essential for today's organisations as they process information more accurately and much faster. That is also the reason why an accounting information system have become an important component of any successful business. QUESTION 5 5.1 Processor task management, Memory management, Device management, File management, Application program interface (API), User interface, and Network capabilities. NOTES Operating system The operating system consists of software, which enables the various parts of a computer system to work together by performing tasks such as transferring data between memory and disks or rendering output to a display device. It also provides a platform on which to run a system and application software, as well as a user interface. An operating system consists of many components. The kernel is the central component of an operating system and controls the most critical processes. It is the link between the email: Tel : 9 Cell : 3 GR TUTORIALS applications and the actual data processing done by the hardware. The kernel provides the most basic services, such as the hardware-software interaction, device management and memory management. The operating system will run more efficiently if the kernel is more efficient. An operating system perform the following important tasks and functions: . Processor task management - the operating system assigns various tasks to the processor and allocates the required computer resources for processing. . Memory management - the operating system controls the allocation of main memory and other storage areas to a system and application software programs. This is to ensure that the memory of the computer system is used to its optimum level to increase the performance and speed of the computer system. . Device management - the operating system uses special programs called drivers that act as translators between the electrical signals of the hardware and the high-level programming languages of the operating system and application software, to communicate and manage hardware devices. For example when a computer system receives input from a keyboard, the electrical impulses are translated by the applicable drivers into computer readable input that is used by the operating system and application software as input. . File management - the operating system ensures that files in the secondary storage are available when needed. It also helps to protect these files from unauthorized access. . Application program interface (API) - an API is a set of commands, functions, and protocols which programmers can use when creating software for a specific operating system. . User interface - the user interface (UI) facilitates interaction between a user and the computer system. New developments in user interfaces have been in the area of the graphical user interface (GUI), providing an easy-to-understand interface for computer users. The input and output peripheral devices are part of the computer's user interface. . Network capabilities - most operating systems include features that help users to connect to computer networks. 5.2 Anti-virus and anti-spam software, Backup utilities, Data compression software, Disk compression utilities, Disk utilities. NOTES Utility software Utility software was developed to help analyse, configure, maintain and optimise a computer system. Utility software usually focuses on how the computer hardware, operating system, application software and data storage operate. Most operating systems usually come with pre-installed utilities. Utility programs can also be purchased and installed separately. -Anti-virus and anti-spam software - These software utilities are generally used to prevent, detect and remove malware, including computer viruses, computer worms, Trojan horses, spyware and adware. Kaspersky Anti-Virus, Norton Anti-Virus, BitDefender Anti-Virus, McAfee, AVG Anti-Virus and Symantec to name just a few -Backup utilities: These utilities create an exact copy of all the information stored on a disk, and are capable of restoring either the whole disk (eg in the event of disk failure) or selected email: Tel : 9 Cell : 3 GR TUTORIALS files (eg in the event of accidental deletion or corruption of a file). Norton Ghost, Acronis True Image and Symantec NetBackup to name just a few. -Data compression software: These utilities are used to reduce the size of files. A compressed file takes up less disk space. It can be transferred to another system or over the internet quicker than an uncompressed version. This is achieved by the software using unique algorithms to compress data by encoding information using fewer bits than the original version would use. A typical utility program used for data file compression is WinZip or 7Zip, which creates compressed zip or 7z files that can be easily unzipped to the original version. Media compression is used to save compressed audio, image and video files. Examples of compressed media file formats include MP3 audio, JPEG images and MPEG video files, which can be played and viewed by media playback programs with built-in encoders that read the compressed file formats. 7-Zip is open-source software. You can use 7-Zip on any computer, including a computer in a commercial organisation. You do not need to register or pay for 7-Zip. For more information visit -Disk compression utilities: These utilities can compress/uncompress the contents of a disk, increasing its storage capacity. Microsoft's Windows disk compression utility. -Disk utilities: Disk utilities including disk storage utilities, disk defragmenters, disk checkers, disk cleaners and disk space analysers. These utilities analyse the disk space, sort files, check for disk errors and areas that are corrupt and clean the disk by deleting redundant files, all of which improves the operating efficiency of the hard drive. Microsoft's Windows error checking and defragmentation tools QUESTION 6 6.1 • Microwave transmission • Satellite transmission • Cellular telephones • Global positioning systems • Cordless computer devices NOTES Wireless transmission With wireless transmission, signals are broadcast as electromagnetic waves through free air space. Wireless signals are transmitted by a transmitter, and received by a receiver. Wireless systems may be inexpensive because no wires need to be installed to transmit the signal. Wireless transmissions are, however, susceptible to both electromagnetic interference and physical interference. Common wireless media include the following: -Microwave transmission Microwave transmissions are high-frequency signals sent through the air using earth-based transmitters and receivers. -Satellite transmission Satellites use microwave radio to transmit information and are capable of transmitting voice, data and TV signals. email: Tel : 9 Cell : 3 GR TUTORIALS -Radio transmission Radio transmissions are signals of electromagnetic waves, which can travel through certain obstructions such as walls. Radio transmissions can be used to transmit voice and data, with both wireless LANs and cellular phones using radio technology. -Infrared transmission Signals in the form of light waves are transmitted through the air between devices, requiring line of sight for transmitting within short distances of less than a few hundred metres. Wireless Channels Examples: • Microwave transmission • Satellite transmission • Cellular telephones • Global positioning systems • Cordless computer devices Wireless channels use wireless technology which can be divided into: • Fixed wireless • Mobile wireless • Portable wireless • Infrared wireless 6.2 • Speed of transmission • Effective rate of transmission • Direction of transmission • Mode of transmission NOTES The efficiency and capabilities of the telecommunication system will be determined by the characteristics of the selected communication channel: • Speed of transmission • Effective rate of transmission • Direction of transmission • Mode of transmission QUESTION 7 7.1 Changes in technology, Changes in decision-making policies, Changes in the needs and demands of users and stakeholders: NOTES REASONS WHY AN INFORMATION SYSTEM NEED TO BE REPLACED OR IMPROVED All business systems should be open systems and these are constantly influenced by changes in the environment. Typical changes include the following: . Changes in technology: New technology can lead to new production processes or communication methods by using new and better equipment, which will affect the information system. . Changes in decision-making policies: For example, decisions to centralise email: Tel : 9 Cell : 3 GR TUTORIALS making and information systems, or to decentralise decision-making and information systems, will lead to a need to replace, change, or improve the existing information systems. . Changes in the needs and demands of users and stakeholders: To improve decisionmaking, the needs of the different users of information change continually. . Changes in the business environment: Organisations need to stay competitive in an environment where the impact of an increasingly global market is enormous. . Changes in the nature of the organisation: Changes in the activities of the organisation; for example more production lines or changes in production lines. This may also occur when two organisations merge. . Changes to maintain a competitive advantage: A constant flow of new ideas and changes are necessary to stay ahead of the competition. . Changes to improve performance and productivity: Re-design of business processes and the information system in order to improve the performance and productivity of the organisation. . Depending on the impact of the change on the current system, a total redesign might be required, or modifications may be made as part of system maintenance.