1.2.3 Software Development

Question 1

Identify the different stages of the Software Development Lifecycle (SDLC)

Answer 1

• Feasibility
• Requirements
• Analysis and design
• Implementation
• Testing
• Evaluation
• Maintenance

Question 2

Feasibility

Answer 2

• Establishes whether or not the project can be done
  Considers factors of the project e.g. technical, economic, legal and political

Question 3

What is a requirement?

Answer 3

• A specific feature of the new system and recorded in a document called requirement specification

Question 4

What key sections can requirements be broken down into?

Answer 4

• Interface: how the user interact with it
• Functional: what the system will do
• Performance: how well/fast will the system respond

Question 5

SDLC: Analysis and Design

Answer 5

• The process of taking the requirements of a new system and deciding what the system will look like, how will it store data
• Design can only go ahead once the requirements specification has been completed
• Each requirement needs to be incorporated into the design

Question 6

Waterfall lifecycle

Answer 6

• Derives its name from cascading effect from one phase to another
• Each phase has a well-defined start and end point with identifiable deliverables

Question 7

Advantages of the waterfall lifecycle

Answer 7

• Simplicity makes it easy to manage
• Everyone on the project is very clear on the responsibilities at each stage
• Clear deliverables
• Easy to see if a project is running to schedule

Question 8

Disadvantages of the waterfall lifecycle

Answer 8

• Carries a lot of risk
• The user doesn’t get to see the product for the first time until the project is near its end
• Misunderstanding requirements can lead to a project that is not easy to fix
• Requirements must be very well understood so this model is not suitable for complex projects

Question 9

Spiral model

Answer 9

• Risk-driven development methodology
• More of a guide for development teams, allowing them to adopt element of one or more other methodologies
• Better thought of as a process model generator, where decisions on the software development methodology are made based on the risk identified

Question 10

Advantages of the spiral model

Answer 10

• Risk management is at the heart of this model
• Excellent for projects that contain a high level of risk

Question 11

Disadvantages of the spiral model

Answer 11

• Complex nature of risk analysis increases costs - risk management is a highly specialised skill
• If risk analysis is done badly, the project suffers

Question 12

Rapid Application Development (RAD)

Answer 12

• Involves producing successive prototypes of the software until a final version is produced and approved