1.2.3 - Software Development

Question 1

8 Stages of Software Development Lifecycle

Answer 1

• Feasibility
• Requirements
• Analysis and Design
• Implementation
• Testing
• Deployment
• Evaluation
• Maintenance

Question 2

5 Software Development Methodologies

Answer 2

• Waterfall
• Rapid Application Development
• Spiral Model
• Agile Methodology
• Extreme Programming

Question 3

Extreme Programming

Answer 3

• A software development methodology that involves paired programming with a focus on high quality code.
• It is designed to allow development to respond to changing user requirements.
• Programs made using this are regularly reviewed/iterative process.

Question 4

Waterfall Model

Answer 4

• Follows a series of stages in order (Analysis/Design/Development/Test).
• Progress to the next step is not made until the previous step is completed.

Question 5

Rapid Application Development

Answer 5

• Prototype is created and evaluated
• Feedback used to inform next iteration
• Any changes are made and the process is repeated until the prototype becomes final product.

Question 6

Spiral Model (HINT - “DOIMR -DTP”)

Answer 6

• The spiral model is a ‘Risk-Driven’ development process with four quadrants (Determine Objectives, Identify and Manage Risk, Develop and Test, Plan next iteration).
• Client feedback then informs future developments and prototypes which feedback into future revisions.

Question 7

Agile Development Methodologies

Answer 7

• Methods designed to cope with changing requirements by producing software in an iterative manner
• Main Example - Extreme, RAD, Spiral

Question 8

What is an example of an agile development methodology

Answer 8

Extreme Programming

Question 9

Advantages of Extreme Programming

Answer 9

• Pair programming ensures the code in each iteration is well-tested, robust and of good enough quality to be used in the final product
• New requirements can be adopted throughout
• An end user is integral throughout
• Code is created quickly and modules become available for use by the client as they are completed

Question 10

Disadvantages of Extreme Programming

Answer 10

• If the developers are split geographically it can cause issues when it is time for code review.
• Emphasis on coding rather than design results in a lack of documentation, making it unsuitable for larger projects
• Heavy time input from the client to feedback and guide the project

Question 11

Advantages of Waterfall Model

Answer 11

• Tends to suit large scale projects with static/stable base requirements
• Focuses on the end user at the start and then they may be consulted at different points throughout the project
• Progress of system development is easily measurable

Question 12

Disadvantages of Waterfall Model

Answer 12

• It can be inflexible and limits changing requirements
• If a change does occur in the requirements the lifecycle cannot respond easily, often at the cost of
  time and money
• System performance cannot by tested until the system is almost fully coded

Question 13

Advantages of Spiral Model

Answer 13

• Large amount of risk analysis ensures the riskiest parts of the project are identified and dealt with first so issues are addressed early in project development
• A software prototype is created early in the life cycle and refined with each spiral iteration

Question 14

Disadvantages of Spiral Model

Answer 14

• Highly skilled development team needed to perform risk analysis
• Development costs can be high due to number of prototypes being created and increased client collaboration

Question 15

Advantages of Rapid Application Development

Answer 15

• Reduced development time due to “time boxing”; each subtask being given a strict time limit
• Increased user involvement so issues can be identified and fixed early / more likely to meet client requirements
• Simple but working deliverable can be released to market very quickly
• Not all requirements need to be stated at the start so therefore it is more flexible

Question 16

Disadvantages of Rapid Application Development

Answer 16

• The emphasis on speed of development may impact the overall system quality initially (before further developments); not suitable for safety-critical systems
• Potential for inconsistent designs and a lack of attention to detail in respect of administration and documentation
• Heavy time input from the client to feedback and guide the project