DESIGNING THE NEW INFORMATION SYSTEM. Lecturer: Prof. E.E Badu, Dept. of Information Studies Contact Information:

Transcription

1 DESIGNING THE NEW INFORMATION SYSTEM Lecturer: Prof. E.E Badu, Dept. of Information Studies Contact Information: College of Education School of Continuing and Distance Education 2017

2 Session Overview Having analyzed your present system as described in the last section, you are ready to propose a computer-based information system for your organization. In other words you have to design a new information system to replace the old system you analyzed. Slide 2

3 Session Outline Upon completing the section you should be able to Design a new computer-based information system Document systems requirement for a new system Design database(s) for your new system Select hardware and software for your new system Slide 3

4 Topic One DESIGNING YOUR NEW COMPUTER- BASED SYSTEM Slide 4

5 DESIGNING YOUR NEW COMPUTER- BASED SYSTEM A new main objective has to be stated for the new system. System requirement for the new system are stated. Based on these requirements, alternative solutions to the problem are put forward. Out of these solutions one is preferred and the justification for the selected one is then documented. Advantages of the proposed system are put forward for management of the organization for which the information system is designed to consider. Constraints about the chosen solutions are outlined. Constraints could be financial, cultural, and any other internal ones. Slide 5

6 DESIGNING YOUR NEW COMPUTER- BASED SYSTEM CONT D There is then the narration of how the system processes are going to be designed supported by appropriate diagrams e.g. system flow charts, data flow diagrams etc. The next stage is description of Input and Output designs as well as files. Output for the new system are designed first. The type of output needed and the required technology are chosen. User interface design is made. After this inputs are designed. The type of input device to be used must be chosen. May be biological feedback, digital collection device, digital camera, MICR systems etc. Slide 6

7 DESIGNING YOUR NEW COMPUTER- BASED SYSTEM CONT D Files and databases are designed and computer programs are written. A second cost benefit analysis is done. Basic cost element will include hardware, software, personnel and other physical resources. Benefit analysis will be the study of the planning control and operating advantage to be gained from developing and using the new information system. Hardware and software considerations are made. The criteria for selecting hardware and software are as follows: Slide 7

8 Topic Two SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM Slide 8

9 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM Factors for the selection of hardware for an automated system. The factors for the selection of hardware can be grouped under Organizational Management Technical Slide 9

10 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D ORGANIZATIONAL FACTORS Organizational factors affect the information system of the organization in a number of ways therefore the following conditions will have to be met in order to select hardware: All computers should have adequate power supply, suitable physical space and a secure environment otherwise they will not operate effectively or may not operate at all. Any standards or regulations regarding hardware selection already in existence must be identified. The operating system and hardware platforms the organization is using must be taken into account so as to create compatible hardware structures. Slide 10

11 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D The network status of the Information System must be known if it is a standalone (computers that operate independently), Local Area Network (LAN), Wide Area Network (WAN) or Intranet (computers that can communicate with each other and software program do not have to reside in the local computer in order to be used. The current network connection and server(s) should be able to interface with and support new hardware. The protocols for connectivity existing in the organization (such as TCP/IP) that would support the new system must be known (protocols are rules for exchanging data between computers). Slide 11

12 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D Security measures must be put in place. Security in terms of unauthorized access and also protection against viruses. The organization must have regular schedule for backing up data. What methods exist in the organization? Is it full disk, mirror back up or selection back up of files that have changed since the last back up. Slide 12

13 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D MANAGEMENT ISSUES The following management issues should be taken into consideration when selecting hardware: There should be protection against power surges. Uninterruptible power supply (UPS) transformers and power surge controls must be part of hardware purchase. When there is sudden power cut, everything in the RAM is lost that is why the RAM is called temporary or volatile storage. Any hardware purchased should be compatible to any computer hardware that may already exist in the information system. Slide 13

14 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D There ought to be a systematic plan for the purchase and maintenance of computers and budgets for hardware purchased and maintenance be integrated into organization wide budget. Maintenance, repairs and replacement needs should be of importance so that computers can be serviced efficiently. Appropriate security or environmental controls should be in place to protect the equipment against theft or natural disasters. Slide 14

15 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D TECHNICAL ISSUES The following are technical issues that should be taken into consideration when selecting hardware: Hardware selected should have storage, processing and memory capacities exceeding the requirements stated by the software. Programs may require more memory capacity than a particular microcomputer offers. Also how much VRAM i.e. Video Random Access Memory is available to computer? Can the RAM and VRAM be upgraded? The RAM also has an effect on the computer can use bigger more powerful programs and these programs can access bigger files. Slide 15

16 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D The speed of the computer should be determined. What are the megahertz (MHz)? Megahertz refers to the speed of the control processing unit (CPU) and determines the rate at which data can be transferred. The more the MHz the better. The system clock controls the speed of operations within a computer. Every computer has an internal clock. Its primary purpose is not to keep time of day. The speed of these clock vibrations or movements determine the speed of processing. The fastest PCs have clock speeds of more than 200 MHz and a CPU operating 133 MHz can process data twice as fast as the same one operating at 66 MHz Slide 16

17 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D Computers that have been configured to support the types of peripheral devices needed for the management of records must be selected. The peripherals in existence should be able to be connected to the new computer. Slide 17

18 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D The Input /Output bus or data bus being used must be determined. A bus connects the parts of the central processing unit (CPU) to each other. The I/O bus is a combination of the hardware and wiring that allows data to be transferred between the internal and external peripheral devices. Example, RAM and ROM chips and parts connecting with outside devices such as monitors, scanners or printers. A bus is a data road way along which bits travel. Such data pathways resemble a multilane highway. The more lanes there are the faster the traffic can go through. Similarly the greater the capacity of a bus, the more powerful and faster the operation. A 64 bit bus has greater capacity than 32-bit bus. Along with the MHz, the bus defines the rate of speed at which data can be transferred. There are 4 principal bus lines or architecture. Slide 18

19 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D Industry Standard Architecture (ISA). This was developed by IBM first as 8-bit wide data path then as 16 bit wide. Micro channel Architecture (MCA). This was developed by IBM after they manufactured the 386 chip. It was a 64 bit bus. Extended Industry Standard Architecture (EISA). This is a 32 bit bus standard which was proposed in September 1988 by 9 manufacturers of IBM compatibles. This consortium of hardware developers opposed TBM s new standard. They were led by Compaq Computer Corporation. The purpose of EISA is to extend and amend the old ISA standard so that all existing expansion boards can work with the new architecture. Like MCA, EISA has introduced a 64 bit bus. Slide 19

20 SELECTING APPROPRIATE HARDWARE FOR A NEW INFORMATION SYSTEM CONT D Peripheral Component Interconnect (PCI). The most recently developed category of buses is called local buses. These buses were originally developed to meet the tremendous video channels of today s graphical user interfaces. PCI is the most widely used local bus. VESA local bus (VL-Bus) is another widely used local bus that is nearly ten times faster than either MCA or EISA. PCI buses are widely used to connect the CPU, memory and expansion boards. PCI is replacing MCA and EISA buses. Slide 20

21 Topic Three SELECTION OF APPROPRIATE SOFTWARE Slide 21

22 SELECTION OF APPROPRIATE SOFTWARE The following are the criteria for selecting the appropriate software for an organization. Software to be selected for an organization must meet the system and functional requirements of the organization. Consideration should be given to short term and long term costs associated with the software. If a particular software does not meet all the needs of the organization, the software agency must be able to provide customization services after installation. Slide 22

23 SELECTION OF APPROPRIATE SOFTWARE CONT D The immediate and ongoing costs of the software such as costs of installation, maintenance, training and cost of manuals must be calculated. Potential costs for upgrades must be assessed over time and provision must be made for these costs. The compatibility of the software with any operating system, hardware and networks already found in the organization should be determined. The memory storage and processing requirements for the new software must be examined. Software manufacturers often list minimal and optimal requirements for memory and data processing. These appear in manuals attached to software. Slide 23

24 SELECTION OF APPROPRIATE SOFTWARE CONT D The software to be selected must have the ability to accept imported data from other systems and also data from new software must be able to be exported to other programs to prepare reports and do presentations. The limitations of the software should be known. This could be the maximum number of users, number of records that can be entered into a database or the volume of transactions that can be handled at a time. The software interface must be identified. Determine if the software is menu or command driven. Find out if it can work in a windows environment. Some interfaces may require additional staff training. Slide 24

25 SELECTION OF APPROPRIATE SOFTWARE CONT D All other features of the software as they relate to information system must be determined. Features such as variable length fields, subject-classification capabilities, indexing, capacity to add (append) modify and delete various levels of the subject classifications system. Software selected must be able to handle authentication and provide selective access to performing actions (such as adding, deleting, editing existing records. Slide 25