2 ICT vs Manual methods of data processing Capabilities & limitation of ICTICT vs Manual methods of data processingCase Study – the school reporting systemYour intermediate reports used to be done by hand, the system has now been computerised.What benefits are there of having a computerised reporting system ?
3 ICT vs Manual methods of data processing Capabilities & limitation of ICTICT vs Manual methods of data processingCase Study – the school reporting systemThe old system was for subject teachers to transfer levels and effort grades from their mark books into a grid for pupils in each form.Image of markbook & grid sheets in here
4 ICT vs Manual methods of data processing Capabilities & limitation of ICTICT vs Manual methods of data processingCase Study – the school reporting systemThese levels and grades were then copied onto pupil report sheets by form teachers.Image of report sheets in here
5 ICT vs Manual methods of data processing Capabilities & limitation of ICTICT vs Manual methods of data processingCase Study – the school reporting systemThe grids and duplicates of the reports were then stored in a room.Image of bundles of reports in here
6 ICT vs Manual methods of data processing Capabilities & limitation of ICTICT vs Manual methods of data processingCase Study – the school reporting systemThe new, computerised system requires teachers to select the class they teach and then enter levels and effort grades into the class list.Image of class list page in here
7 ICT vs Manual methods of data processing Capabilities & limitation of ICTICT vs Manual methods of data processingCase Study – the school reporting systemThe data for each pupil is then processed and printed.Image of final printout in here
8 ICT vs Manual methods of data processing Capabilities & limitation of ICTICT vs Manual methods of data processingCase Study – the school reporting systemConsider the two systems and using a table (full page of A4 with explanations) make a comparison of the two systems :ManualComputerisedRepetitive processingSpeed of processingData storage capacitySpeed of searchingAccuracy & speed of data communicationsAbility to produce different output formats
9 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsConsider the effects of :HardwareSoftwareSuitability of operating systemCommunicationGIGO
10 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsHardware :Does the existing hardware meet minimum specifications for the software? Ideally it should meet the recommended specification.System Requirements Minimum System Requirements: Intel® Pentium® or AMD® Athlon® 2 GHz 512 MB RAM Windows® XP or Windows 2000 (XP recommended) USB 2.0 port Direct X® compatible graphics card (ATI® Radeon® or NVIDIA® GeForce" or higher recommended) Direct X compatible sound card 650 MB hard disk space DVD burner, mouse, CD-ROM drive Hardware specifications: External Hi-Speed USB 2.0 video capture device Composite video input (RCA connector) S-Video input (mini-DIN connector) Stereo audio input (2 x RCA connectors)
11 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsSoftware : (object linking and embedding)OLE allows information to be shared between different programsFor example, a spreadsheet created in Excel can be included in a Word document either by embedding it in the document, or by creating a link from the document.An embedded object has no connection with its original source file.A linked object ensures that the information displayed in the document will always be displayed – via the link – directly from the source file.
12 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsSoftware :Linked objectoriginal information remains in the source filedestination file displays a representation of the linked information but stores only the location of the original datalinked information is updated automatically if you change the original data in the source fileUse if file size is a considerationEmbedded objectbecomes part of destination file.because an embedded object has no links to the source file, the object is not updated if you change the original data
13 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsSoftware :Consider the data processing efficiency of a piece of software in terms of :Ease of data entrySpeed of processingCompatibilityMemory requirementsUnnecessary features
14 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsSuitability of operating systemOperating systems available are :Windows – most common PC op sysOSX (Panther) – most common apple mac op sysUnix/Linux – GUI similar to windows but open sourceMSDOS – command line driven op sys
15 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsSuitability of operating systemOperating systems deal withMemory management.Resource allocation and schedulingBacking store managementInterrupt handlingAllowing a user to communicate with the computerControlling peripheral devicesIf the operating system does not run efficiently then the application software will not run efficiently.
16 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsCommunicationIf an application is being used on a network machine and the processing is taking place over the network (grid processing) then the efficiency & capability of the network becomes a factor when considering efficiency of processing.GIGO – garbage in = garbage outIf the data entry method is inefficient or input data is not valid then the efficiency of processing is affected – errors will occur during the data processing stage.
17 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsOther factors affecting efficiencyChange in circumstance during software developmentSoftware takes a long time to develop, if during this time another product comes onto the market or a new system is released (win 98 vs win XP) then the development of the software is affected.Speed of implementationOnce an organisation has acquired software it has to implement it, this involves installing & training. This has a direct affect on processing efficiency
18 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsOther factors affecting efficiencyCompatibilityWhen windows XP was released, users who upgraded from win 98 suddenly found that their scanners / printers / applications would not work – oops.Insufficient testingSoftware development is a very competitive field with pressure to release products ahead of the field. As a result, software is sometimes not fully tested.
19 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsOther factors affecting efficiencyPoor communication with userThe user interface may not be very friendly (how ?)Validation rules may not have sensible error messages, informing the user of their mistakeThe instruction manual could be poor
20 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsAbility of userIf the user is clueless then the efficiency of data entry / processing is affected.It has been postulated that if a monkey randomly hit keys on a PC for 10,000 years then at some point they would type the entire works of Shakespeare !
21 Capabilities & limitation of ICT Factors affecting the efficiency of data processing systemsPoor post implementationPost implementation is the procedures / actions that are carried out after the software has been installed. These could be :TrainingMonitoringEvaluation
22 Required for a number of reasons Capabilities & limitation of ICTFactors affecting the efficiency of data processing systemsMaintenance proceduresRequired for a number of reasonsErrors may appear in the softwareOriginal requirements are modifiedHardware developments may make it desirable to change the software to take advantageNew legislation may be introduced
23 Factors affecting the efficiency of data processing systems Types of maintenancePerfective maintenance system can be made better in some way without changing its functionality.Adaptive maintenance changing needs in a company may mean systems need to be adapted – e.g. a single-user system may be adapted to a multi-user system.Corrective maintenance involves correction of previously undetected errors. e.g. the millennium bug. Many major programs are released with ‘bugs’ that require maintenance releases – ‘patches’ or ‘service packs’ to fix them (most of the Microsoft products)
24 Types of maintenance (cont) Process triggered by: Factors affecting the efficiency of data processing systemsTypes of maintenance (cont)Process triggered by:user or management requestsFurther development by manufacturerCost and impact on system are assessed for feasibilityNew release has to be programmed and testedSoftware packages generally have release numbersMinor releases are indicated by a change in number suffix e.g. 3.0 to 3.1 with WindowsMajor releases are often indicated by a change like 4.0 to 5.0 or by a change in name
25 Types of maintenance (cont) Factors affecting the efficiency of data processing systemsTypes of maintenance (cont)Most software developers would prefer to be working on exciting new projectsMaintenance is very expensiveCost-effectiveness depends uponA clearly-defined and well-documented original systemSuitably qualified and informed analysts and programmersA clear and uncomplicated dialogue path between user and developerA transparent structure that allows analysts and programmers to assess fully the impact of any changesLimiting the amount of change at any one time
26 Cost Factors affecting the efficiency of data processing systems Cost can be considered in terms of money, time and human resources.If a system has a high financial cost and takes a long time to be implemented or process data then it would be considered inefficient.
27 Hardware Factors affecting the efficiency of data processing systems (refer previous notes)The hardware that is needed to run software efficiently is a factor to be considered :Is the hardware powerful enough to run the software ?Is the hardware reliable enough ?Is new hardware needed to run the software ?Is the hardware compatible (mac vs PC)
28 Support Factors affecting the efficiency of data processing systems When you purchase software you often receive a form of support.This may be in the form of :Help filesOnline (internet) helpTechnical advice over the phoneEngineer calloutsUpdates
29 Nature & Capabilities of Software What is software?Types of softwareGeneric softwareDrivers, protocols and standards for interfacing with peripherals and storage devicesObject linking and embeddingFunctionality of internet softwareCompatibility and portabilityFeatures of software & evaluation/comparisonUpgrading - technical and human implicationsReliability - how do we make software reliable?
30 Nature & Capabilities of Software What is software?Hardware is the physical components that make up a computer system.Software is the programs and data that make the hardware do something useful.Software is NOT the CD or floppy disc that the program comes on - usually you are just buying the licence to use the software, and not the software itself.
31 Nature & Capabilities of Software FirmwareYou may also come across the term Firmware - this is software that is stored in hardware (i.e. on a chip) and is usually found in embedded systems.Not all computers are multi-purpose desktop or laptop PCs, mainframe or mini-computers, so are designed for a specific purpose and are built into machinery - these are called embedded systems.Embedded systems are mostly used for control, e.g. in washing machines.
32 Nature & Capabilities of Software Types of SoftwareThere are three main categories of software:Operating systemsUtility programsApplicationsApplications come in different types :Specific purpose - e.g. Encarta, POS, etc.Generic - e.g. spreadsheets, databases, etc.Off the shelf - i.e. a product such as Sage AccountsBespoke - i.e. custom-made for the user
33 Nature & Capabilities of Software Operating SystemsControl and manage the computer’s resourcesmemory managementresource allocationstoragecommunicationinterrupt handlingExamples include Windows (NT, 2000 and XP only, not versions up to 98), Unix, Linux, CPM, Mac-OS.Heathcote says that they are installed on the hard disc, but this is not always the case, e.g. RISC-OS, PDAs, embedded systems and early home computers such as Spectrums and VIC-20s!
34 Nature & Capabilities of Software Operating SystemsShellThe kernel is hardware specific and controls primary and secondary storage, input and output.KernelThe shell provides the user interface - this could be a command line or a Graphical User Interface.It is possible that an operating system, e.g. Windows NT or Linux, could run on several platforms (e.g. Intel, Power PC, DEC Alpha) by having the same shell with different kernels
35 Nature & Capabilities of Software Memory ManagementSystem resources and hardware often require memory which must be allocated by the OSMost modern operating systems are capable of multi-tasking (running several programs at once) - each program will require its own area of memory to store data.Some types of OS can use multiple processors, so they must also decide where a process takes places, as well as which memory it will use!
36 Nature & Capabilities of Software Memory ManagementPrimary storage (e.g. RAM):Volatile - i.e. contents are lost without powerFast - access time of around 7ns for PC RAMRelatively expensive - 1Gb DDR RAM costs £140Secondary storage (e.g. hard disc):Non-volatile, usually magnetic media - stored without powerSlower - access time of around 8msCheaper, e.g. 40Gb for £35
37 Nature & Capabilities of Software Virtual MemorySometimes the operating system can use secondary storage to supplement primary storage in a way that is transparent to the application - this is called virtual memoryRAM overflows onto the disc - e.g. in the Windows paging/ swap-file
38 Nature & Capabilities of Software Disc Storage SectorConstant angular velocityConstant linear velocityCLV discs (e.g. Compact Discs) slow down as sectors nearer the edge are read - the sectors are the same physical length so that capacity is increased
39 File Allocation and Fragmentation Nature & Capabilities of SoftwareFile Allocation and FragmentationFile A is writtenAFile B is writtenFile A is editedBBADisc is fragmentedThe disc is now defragmented - the sectors are contiguous and so quicker to readLocation of file is stored in the File Allocation Table (FAT)BBBA
40 Nature & Capabilities of Software User InterfaceGUIWIMPMenuCommandManages multi-tasking – e.g. each application in a separate windowAllocates events to the appropriate application:Mouse movementMouse click/double-clickKey pressesTimersShellKeystrokesMouse movements or clicks
41 Nature & Capabilities of Software User InterfaceProvides the ability to transfer information between applications – e.g. the clipboard in WindowsClipboardApplication AApplication BCopyPasteProvides a consistent appearance to applications, e.g. menus, help, printing and error messages
42 Nature & Capabilities of Software PeripheralsPeripherals can be connected to a computer either internally - e.g. video or sound cards - or externally, through USB, serial or parallel ports.Internal devices are serviced through interrupts - the OS polls each device in turn to see whether it requires any processing time.The operating system communicates with the device through a driver.A driver is a piece of software that translates the user’s instructions - e.g. that they want a particular piece of text to be bold - into the device-specific control codes that the particular hardware uses.
43 Nature & Capabilities of Software Utility ProgramsA utility is a small program, usually with a technical function - they often come with an operating system.Examples of utilities are:Virus checkersWindows Explorer/File Manager/XtreePrinter ManagerScandisk & DefragWinzip (or other compression software)Norton Utilities/PC ToolsCompilers and interpretersPerformance monitoringBackup and restore
44 Nature & Capabilities of Software ApplicationsWritten for a specific purpose - inflexibleSuch systems may be bespoke or off-the-shelfBespoke systems are those written specifically for a particular customer, usually in a language such as C++, Visual BASIC or Java, e.g.Point of Sale (POS) systemsInsurance quotation systemsManagement Information Systems (MIS)Off-the-shelf software is the boxed products you might see in PC World:Sage AccountingAutoRoute
45 Nature & Capabilities of Software Bespoke SoftwareMore likely to be bug-riddenTied into one suppliers, e.g. for:documentation (no books!)trainingsupportPortability of data is less likelyMuch more expensivePurpose-designed for task - it does exactly what you want (or what you asked for, anyway!)Purpose-designed for hardwareExtra features can be integrated more easily
46 General Purpose/Generic Software Nature & Capabilities of SoftwareGeneral Purpose/Generic SoftwareSome software wasn’t designed for a specific purpose - they are known as generic or content-free applicationsExamples of generic software include:word processors and DTP applicationsdatabase management systemsspreadsheetsIntegrated packages contain several of these functions in one application - e.g. Microsoft Works or Lotus SymphonySoftware suites contain these functions in separate applications, e.g. Microsoft Office or Lotus SmartSuite