1. Unit 1B – Capabilities & limitations of ICT

2. ICT vs Manual methods of data processing
Capabilities & limitation of ICT
ICT vs Manual methods of data processing
Case Study – the school reporting system
Your 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 ICT
ICT vs Manual methods of data processing
Case Study – the school reporting system
The 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 ICT
ICT vs Manual methods of data processing
Case Study – the school reporting system
These 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 ICT
ICT vs Manual methods of data processing
Case Study – the school reporting system
The 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 ICT
ICT vs Manual methods of data processing
Case Study – the school reporting system
The 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 ICT
ICT vs Manual methods of data processing
Case Study – the school reporting system
The 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 ICT
ICT vs Manual methods of data processing
Case Study – the school reporting system
Consider the two systems and using a table (full page of A4 with explanations) make a comparison of the two systems :
Manual
Computerised
Repetitive processing
Speed of processing
Data storage capacity
Speed of searching
Accuracy & speed of data communications
Ability to produce different output formats

9. Capabilities & limitation of ICT
Factors affecting the efficiency of data processing systems
Consider the effects of :
Hardware
Software
Suitability of operating system
Communication
GIGO

10. Capabilities & limitation of ICT
Factors affecting the efficiency of data processing systems
Hardware :
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 systems
Software : (object linking and embedding)
OLE allows information to be shared between different programs
For 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 systems
Software :
Linked object
original information remains in the source file
destination file displays a representation of the linked information but stores only the location of the original data
linked information is updated automatically if you change the original data in the source file
Use if file size is a consideration
Embedded object
becomes 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 systems
Software :
Consider the data processing efficiency of a piece of software in terms of :
Ease of data entry
Speed of processing
Compatibility
Memory requirements
Unnecessary features

14. Capabilities & limitation of ICT
Factors affecting the efficiency of data processing systems
Suitability of operating system
Operating systems available are :
Windows – most common PC op sys
OSX (Panther) – most common apple mac op sys
Unix/Linux – GUI similar to windows but open source
MSDOS – command line driven op sys

15. Capabilities & limitation of ICT
Factors affecting the efficiency of data processing systems
Suitability of operating system
Operating systems deal with
Memory management.
Resource allocation and scheduling
Backing store management
Interrupt handling
Allowing a user to communicate with the computer
Controlling peripheral devices
If 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 systems
Communication
If 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 out
If 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 systems
Other factors affecting efficiency
Change in circumstance during software development
Software 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 implementation
Once 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 systems
Other factors affecting efficiency
Compatibility
When windows XP was released, users who upgraded from win 98 suddenly found that their scanners / printers / applications would not work – oops.
Insufficient testing
Software 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 systems
Other factors affecting efficiency
Poor communication with user
The user interface may not be very friendly (how ?)
Validation rules may not have sensible error messages, informing the user of their mistake
The instruction manual could be poor

20. Capabilities & limitation of ICT
Factors affecting the efficiency of data processing systems
Ability of user
If 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 systems
Poor post implementation
Post implementation is the procedures / actions that are carried out after the software has been installed. These could be :
Training
Monitoring
Evaluation

22. Required for a number of reasons
Capabilities & limitation of ICT
Factors affecting the efficiency of data processing systems
Maintenance procedures
Required for a number of reasons
Errors may appear in the software
Original requirements are modified
Hardware developments may make it desirable to change the software to take advantage
New legislation may be introduced

23. Factors affecting the efficiency of data processing systems
Types of maintenance
Perfective 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 systems
Types of maintenance (cont)
Process triggered by:
user or management requests
Further development by manufacturer
Cost and impact on system are assessed for feasibility
New release has to be programmed and tested
Software packages generally have release numbers
Minor releases are indicated by a change in number suffix e.g. 3.0 to 3.1 with Windows
Major 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 systems
Types of maintenance (cont)
Most software developers would prefer to be working on exciting new projects
Maintenance is very expensive
Cost-effectiveness depends upon
A clearly-defined and well-documented original system
Suitably qualified and informed analysts and programmers
A clear and uncomplicated dialogue path between user and developer
A transparent structure that allows analysts and programmers to assess fully the impact of any changes
Limiting 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 files
Online (internet) help
Technical advice over the phone
Engineer callouts
Updates

29. Nature & Capabilities of Software
What is software?
Types of software
Generic software
Drivers, protocols and standards for interfacing with peripherals and storage devices
Object linking and embedding
Functionality of internet software
Compatibility and portability
Features of software & evaluation/comparison
Upgrading - technical and human implications
Reliability - 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
Firmware
You 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 Software
There are three main categories of software:
Operating systems
Utility programs
Applications
Applications 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 Accounts
Bespoke - i.e. custom-made for the user

33. Nature & Capabilities of Software
Operating Systems
Control and manage the computer’s resources
memory management
resource allocation
storage
communication
interrupt handling
Examples 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 Systems
Shell
The kernel is hardware specific and controls primary and secondary storage, input and output.
Kernel
The 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 Management
System resources and hardware often require memory which must be allocated by the OS
Most 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 Management
Primary storage (e.g. RAM):
Volatile - i.e. contents are lost without power
Fast - access time of around 7ns for PC RAM
Relatively expensive - 1Gb DDR RAM costs £140
Secondary storage (e.g. hard disc):
Non-volatile, usually magnetic media - stored without power
Slower - access time of around 8ms
Cheaper, e.g. 40Gb for £35

37. Nature & Capabilities of Software
Virtual Memory
Sometimes the operating system can use secondary storage to supplement primary storage in a way that is transparent to the application - this is called virtual memory
RAM overflows onto the disc - e.g. in the Windows paging/ swap-file

38. Nature & Capabilities of Software Disc Storage
Sector
Constant angular velocity
Constant linear velocity
CLV 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 Software
File Allocation and Fragmentation
File A is written A
File B is written
File A is edited B B A
Disc is fragmented
The disc is now defragmented - the sectors are contiguous and so quicker to read
Location of file is stored in the File Allocation Table (FAT) B B B A

40. Nature & Capabilities of Software
User Interface
GUI
WIMP
Menu
Command
Manages multi-tasking – e.g. each application in a separate window
Allocates events to the appropriate application:
Mouse movement
Mouse click/double-click
Key presses
Timers
Shell
Keystrokes
Mouse movements or clicks

41. Nature & Capabilities of Software
User Interface
Provides the ability to transfer information between applications – e.g. the clipboard in Windows
Clipboard
Application A
Application B
Copy
Paste
Provides a consistent appearance to applications, e.g. menus, help, printing and error messages

42. Nature & Capabilities of Software
Peripherals
Peripherals 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 Programs
A utility is a small program, usually with a technical function - they often come with an operating system.
Examples of utilities are:
Virus checkers
Windows Explorer/File Manager/Xtree
Printer Manager
Scandisk & Defrag
Winzip (or other compression software)
Norton Utilities/PC Tools
Compilers and interpreters
Performance monitoring
Backup and restore

44. Nature & Capabilities of Software
Applications
Written for a specific purpose - inflexible
Such systems may be bespoke or off-the-shelf
Bespoke 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) systems
Insurance quotation systems
Management Information Systems (MIS)
Off-the-shelf software is the boxed products you might see in PC World:
Sage Accounting
AutoRoute

45. Nature & Capabilities of Software
Bespoke Software
More likely to be bug-ridden
Tied into one suppliers, e.g. for:
documentation (no books!)
training
support
Portability of data is less likely
Much more expensive
Purpose-designed for task - it does exactly what you want (or what you asked for, anyway!)
Purpose-designed for hardware
Extra features can be integrated more easily

46. General Purpose/Generic Software
Nature & Capabilities of Software
General Purpose/Generic Software
Some software wasn’t designed for a specific purpose - they are known as generic or content-free applications
Examples of generic software include:
word processors and DTP applications
database management systems
spreadsheets
Integrated packages contain several of these functions in one application - e.g. Microsoft Works or Lotus Symphony
Software suites contain these functions in separate applications, e.g. Microsoft Office or Lotus SmartSuite