System life cycle (A Level) flashcards

Topic 16: System life cycle

Name the stages of the system life cycle in order

Analysis, design, development and testing, implementation, documentation, evaluation, then maintenance.

User requirements specification vs design specification

The user requirements specification says what users need. The design specification says how the system will be built.

Data flow diagram vs system flowchart

A DFD shows the movement of data. A system flowchart shows hardware, files and processes.

Phased vs pilot implementation

Phased: one part of the system is introduced everywhere at a time. Pilot: the whole system is introduced in one place first.

Waterfall vs agile development

Waterfall completes one stage at a time with sign-off: a clear plan, but late changes are expensive. Agile uses short cycles with close customer contact: it handles changing needs but needs constant user time.

What is RAD?

Rapid application development: fast prototypes, workshops with users and strict time limits. Quick and user-focused, but poor for large, complex systems.

Evolutionary vs throwaway prototyping

An evolutionary prototype is refined until it becomes the final system. A throwaway prototype is discarded once the requirements are clear.

Name the four types of maintenance

Corrective (fix a fault), adaptive (the environment changed, e.g. law or operating system), perfective (users want improvements) and preventive (reduce the risk of future faults).

What criteria are used to evaluate a system?

Efficiency, ease of use and appropriateness for its intended use, judged by checking against the specifications and user requirements and collecting user feedback.