1.6 Software Development

Question 1

Software Development Life Cycles

Answer 1

Analysis Stage: Stakeholders input product requirements
- Define problem & system requirements by:
- Analysing current problem-solving methods
- Considering data types & volume

Design Stage: New system aspects designed, including:
Inputs, Outputs, Security features, Hardware setup, User interface & Creation of a test plan

Development Stage:
- Use design to break project into modules
- Allocate modules to teams for programming

Testing Stage: Various types of testing conducted:
- Alpha testing: In-house, bug identification
- Beta testing: End-user feedback
- White box testing: All possible routes tested
- Black box testing: Input-output testing

Implementation Stage: Software installed after necessary testing

Evaluation Stage: Assess software effectiveness against defined requirements
- Consider criteria like robustness, reliability, portability, maintainability

Maintenance Stage: End-user feedback for errors/improvements
- Regular software updates for bug fixes, security, and improvements

Question 2

Waterfall Lifecycle

Answer 2

• Software development follows sequential series of stages from start to finish
• Analysis Stage: Includes a feasibility study using ‘TELOS’ (Technical, Economic, Legal, Operational, Scheduling) to evaluate project feasibility
• Inflexible, unsuitable for projects w/ changing requirements.
• User involvement limited to initial & final stages
• Stages progress linearly, cannot revisit prior stages easily-
• Used for low risk, general purpose software

Question 3

Agile Methodologies

Answer 3

• Collection of methodologies that enhance development flexibility & adaptability to user requirement changes
• Different stages developed simultaneously (E.g design & analysis)
• Delivery of a working prototype w/ iterative improvements
• Poor documentation, requires consistent interaction
• Used for small-medium projects

Question 4

Extreme Programming

Answer 4

• Agile model focused on a pair of programmers working w/ end-user representative
• System requirements based on “user stories” provided by end-users, guiding program design
• Enhances code quality through continuous critique & improvement during code writing
• Each cycle iteration results in “working version” of program
• High-quality code, high usability
• Effective communication is vital, High cost
• Small-med projects w/ high useability

Question 5

Spiral

Answer 5

• Aimed at managing high-risk projects effectively through four key stages:
  
  • Analyzing system requirements
  • Identifying & mitigating risks
  • Development, testing, & implementation
  • Evaluating to guide next iteration
• Thorough risk analysis, caters to changing needs
• Expensive, lack of focus on code efficiency
• Suited for very large-scale projects due to its cost-intensive nature

Question 6

Rapid Application Development (RAD)

Answer 6

• Iterative methodology useing partially functioning prototypes that are continually built-upon
• User requirements initially gathered w/ focus groups & used to develop an ‘incomplete’ version of the solution given to the user to trial
• Feedback used to generate the improved prototype, continuing until prototype matches requirements, becoming the final product
• Caters to changing user requirments
• Poor documentation, fast pace reduces code quality
• Small-med low budget projects w/ short time frames