1. ACSC 155 System Analysis and Design 5. Input/Output Design
Dr. Stephania Loizidou Himona

2. Dr. Stephania Loizidou Himona
Input/Output Design
User Interfaces
Dr. Stephania Loizidou Himona

3. Data Entry Methods and Devices
Keyboard
(QWERTY)
Ergonomic
Touch-sensitive
Musical
Mouse
Dr. Stephania Loizidou Himona

4. Dr. Stephania Loizidou Himona
Keyless Data Entry
OCR (optical character reader)
OMR (optical mark reader)
MICR (magnetic ink character reader)
Barcode readers
Pen Input
Scanners
Graphics Tablet
Microphones
Dr. Stephania Loizidou Himona

5. Output Methods and Devices
Screens
Printers
Speakers
Dr. Stephania Loizidou Himona

6. Graphical User Interfaces (GUIs)
A method of user communication with an operating system. Basically, to give commands.
By selecting icons, buttons, bars or boxes.
Quick and easy to learn.
Promote standardisation of application program interfaces.
Reduce errors.
Dr. Stephania Loizidou Himona

7. System User Issues for Input Design
Volume of input should be minimised
Enter only variable data, do not enter constant data
Do not input data that can be calculated or stored in computer programs
Use codes for appropriate attributes
Source documents should be easy for system users to complete
Include instructions for completing the form
Minimise the amount of handwriting
Dr. Stephania Loizidou Himona

8. Dr. Stephania Loizidou Himona
Design documents so that they can be easily and quickly entered into the system
Data to be entered should be sequenced
Portions of the form that are not to be input are placed in or about the lower right portion of the source document
Dr. Stephania Loizidou Himona

9. System User Issues for Output Design
Computer outputs should be simple to read and interpret
The timing of computer outputs is important
The distribution of computer outputs must be sufficient to assist all relevant system users
The computer outputs must be acceptable to the system users who will receive them
Dr. Stephania Loizidou Himona

10. Internal Controls for Inputs and Outputs
The number of inputs should be monitored
Care must also be taken to ensure that the data is valid
The timing and volume of each output must be precisely specified
The distribution of all outputs must be specified
Access controls are used to control accessibility of video (on-line) outputs
Control totals should be incorporated into all reports
Dr. Stephania Loizidou Himona

11. Dr. Stephania Loizidou Himona
ISAM – Indexed sequential access method
For storing data records on a physical storage device in sequential order for sequential processing
Allows direct access to the particular record
Batch mode versus On-line processing
Methods of interacting with a system
- command language
- menu
- form
- object
- natural language
Dr. Stephania Loizidou Himona

12. Fourth-generation language
Extremely sophisticated languages
Little or no professional programming skills
Categories (7):
Query languages
Report generators
Graphics languages
Application generators
Very high-level programming languages
Application software packages
Microcomputer tools
Dr. Stephania Loizidou Himona

13. Dr. Stephania Loizidou Himona
Testing and Debugging
Testing
Black box testing
White box testing
Alpha and Beta testing
Selection of test data
Dr. Stephania Loizidou Himona

14. Dr. Stephania Loizidou Himona
Debugging (Errors or bugs)
Translator diagnostics
Cross-referencing, Traces, Variable dumps
Dry runs
Splitting the program
Test strategies
Dr. Stephania Loizidou Himona

15. Installation - Integration
Parallel running
Pilot running
Big bang, or direct change
Phasing
Dr. Stephania Loizidou Himona