Maintenance/Evolution

Question 1

What is code maintenance?

Answer 1

• Correcting errors which were not discovered in earlier stage of the life cycle
• Updating the implementation for updating platforms
• Enhancing the system services as new requirements are discovered

Question 2

What are the types of code changes you can have in the maintenance phase?

Answer 2

Fault repairs
Environmental adaptations
Functionality additions

Question 3

Explain fault repairs

Answer 3

Fixing coding errors
Cost: cheap
Doesn’t involve much redesign

Question 4

Explain environmental adpatation

Answer 4

Updates for new OS
Cost: A little more expensive than fault repairs
Doesn’t involve much redesign

Question 5

Explain functionality additions

Answer 5

Meet business changes
Cost: Expensive, most common too!
Often involves redesign

Question 6

Why is change expensive?

Answer 6

Poor original development practices

Question 7

What are some poor original development practices?

Answer 7

Undocumented requirements
- Cant tell whats changed
Undocumented designs
- Cant understand plan
Low readability of code
- Cant figure out whats going on
Limited documentation

Question 8

What is requirements change management?

Answer 8

The process of understanding and controlling change to requirements

Question 9

What is the process of requirements change management?

Answer 9

• Don’t start with code
• Start by understanding the change and cost (big, small, easy, hard)
• Decide whos paying

Question 10

What are emergency changes in code?

Answer 10

Problems which occur that require fast or emergency changes
- Updating code takes priority over documentation

Question 11

What are the dangers of emergency changes in code?

Answer 11

• Multiple subsequent emergency repairs occur which mask the original emergency repairs
• Code gets unmanageable/ unmaintainable

Question 12

When do we start code again?

Answer 12

Cost of change gets high
- Client notes it is costing a lot to have changes
- Software company realises code is getting hard to fix

Question 13

How is maintenance different to software engineering?

Answer 13

Most SE involved the reuse or previous code
Evolution is another SE loop

Question 14

Why is the maintenance of software important?

Answer 14

• Code can easily adapt to changing needs
• Minimising risks and costs
• Enhancing customer satisfaction