Feasibility

Analysis

Design

Solution

Test

Installation

Train

Evaluate

Maintenance

• operational
• technological
• financial

• background
• analyse
• detailed specification for requirements of new system
• Data Flow Diagram
• Entity-Relation diagram for current system

• HCI
• input
• output
• help
• error messages
• data storage
• record structure
• security and integrity
• E-R model
• method of data entry and validation
• list fields
• module structure chart
• test strategy including test data


• Top down design - break large problems down into smaller problems which can be written as self-contained modules
• Jackson structure diagram - shows how modules all relate to form the whole solution
• Entity-Relation diagram to describe solution
• Pseudo-code

• build solution
• test it
• technical documentation
• user documentation
• train
• install

• programmer follows through code manually using test data to check algorithm is correct
• for locating run time errors

Unit testing - test each individual subroutine or module in a suite of programs

Integration testing - test a complete suite of programs to ensure that they all function correctly when put together

• corrective - problems which occur after system has been in use for a short time and were missed by the testing
• adaptive e.g. changes in VAT
• perfective

• effectiveness
• usability
• maintainability

HCI - interaction between user and computer

• safely
• effectively
• efficiently
• enjoyably

• quick and concise
• requires user to know the commands

• full screen menu e.g. front end of an application
• pull-down menu
• pop-up menu

• too ambiguous
• no training necessary
• less concise than 'artificial language'

• title
• not cluttered
• indicate length of words to be input
• opportunity to go back and make changes
• logical order
• default values where possible to minimise data entry
• full exit and help facilities

WIMP interface (Windows, Icons, Mouse Pointers)

Common User Interface

• increase speed of learning
• greater range of software available to average user

• e.g. used by bank computer connected by telephone which could read out a customer's account balance
• use phonemes (individual sounds from which all words are constructed in any particular language)