1.2.3 Software Development

Question 1

What are the main stages of software development?

Answer 1

Analysis, Design, Implementation, Evaluation and maintenance.

Question 2

What happens during the analysis stage of software development?

Answer 2

The stakeholders state what they require from the project. This is used to define the system requirements.

Question 3

How could system requirements be defined?

Answer 3

Strengths and weaknesses that exist in the current ways that the problem is being solved.
How the project will be used in the future.
Data that’s expected/required.

Question 4

What happens in the design phase of software development?

Answer 4

The different aspects of the new system are designed and planned for.

Question 5

What might be designed and planned in the design phase of software development?

Answer 5

Inputs and outputs (volumes, methods and frequency).
Hardware requirements.
User interface.
Data structures.
Security features.
Testing.

Question 6

What happens in the implementation stage of software development?

Answer 6

Coding and testing takes place. Errors are traced and corrected.
Any user and technical documentation is written.
Once complete, software is installed on the users computer.
It is likely that new issues will arise from this point and will require further development.

Question 7

What happens in the testing stage of software development?

Answer 7

Programs are tested against those outlined in the design phase. Some testing will take place during development (iterative) and some after (post development).

Question 8

What are the different types of testing?

Answer 8

Black box.
White Box.
Alpha.
Beta.

Question 9

What is black box testing?

Answer 9

Testing that’s carried out independently of the code. Uses test data that covers the inputs outputs and functions of the program.

Question 10

What is white box testing?

Answer 10

Testing the codes logic. Tests are devised so that each path through the program is tested.

Question 11

What is alpha testing?

Answer 11

Testing carried out by the software development team.

Question 12

What is beta testing?

Answer 12

Software is given to a selection of the end users who can report any faults to inform the next stages of development. Real users, who don’t understand the code, may try and do things that the developer didn’t anticipate.

Question 13

What happens in the evaluation stage of software development?

Answer 13

The effectiveness of the software is evaluated against the system requirements. To see if it solves the problem outlined in analysis, how effective, usable, reliable, portable and maintainable the solution is.

Question 14

What happens in the maintenance stage of software development?

Answer 14

Any errors or improvements to the system are flagged up. Programmers then issue updates to fix any bugs, security issues or to add improvements.

Question 15

What are the types of maintenance?

Answer 15

Corrective.
Adaptive.
Perfective.

Question 16

What is corrective maintenance?

Answer 16

Correcting bugs that are found once releaced

Question 17

What is adaptive maintenance?

Answer 17

User requirements may change so the software will have to adapt to meet the new needs.

Question 18

What is perfective maintenance?

Answer 18

Making improvements to the software.
Even if the software works there could be ways of improving it - making it easier to use, faster or adding more functuallity.

Question 19

What happens in the waterfall lifecycle model?

Answer 19

Each stage of the software development cycle is completed and documented before the next stage is started. Customers don’t see the end product until it is finished as there isn’t too much to show until its done. Any changes to the project often mean starting again or redoing lots.

Question 20

What are the advantages of the waterfall lifecycle model?

Answer 20

Simple to understand and use.
Each stage is separate and self-contained with well defined outcomes.
Makes project management quite straight forward.

Question 21

What are the disadvantages of the waterfall lifecycle model?

Answer 21

Not much user involvement after the analysis stage once the specification document is made.
No working software is made until late into the cycle.
User is presented with a finished product and if its not exactly what is needed then its typically too late to make any changes.

Question 22

When is the waterfall lifecycle model best used?

Answer 22

When the requirements are clear and fixed (no ambiguities).
The technology is well understood.
The project is short.

Question 23

What is the spiral model of software development?

Answer 23

The project passes through each stage of the cycle repeatedly. Each successive loop of the spiral produces a more refined prototype until the software meets all of the requirements.

Question 24

What are the advantages of the spiral model?

Answer 24

Well defined steps make the project easy to manage.
Software is produced early on in the process so problems can be identified and dealt with early.
The user gives feedback on each prototype and any required changes are made earlier in the process.
Functionality can be added during the process.
End result is more likely to be what the user wants.

Question 25

What are the disadvantages of the spiral model?

Answer 25

Takes longer to produce an outcome.
makes it more costly to develop due to the time involved.
Doesn’t work for smaller projects

Question 26

When is the spiral model used for software development?

Answer 26

Medium to high risk projects.
Projects where the user is unsure of what they need and what the possibilities are.
Projects with complex requirements.
Large projects that may take years to develop - as technologies may change during the process, meaning the project also has to change.

Question 27

What is the Agile method of software development?

Answer 27

Where software is made in rapid incremental cycles where each version builds on the functionality of the previous. Allows for non-sequential development so all the stages of the cycle can happen at once. Each version being thoroughly tested. The end user is hevily involved with the process and provides feedback at the end of each cycle. Each cycle produces a prototype so there is working code early on in development.

Question 28

What are the advantages of of the agile method for software development?

Answer 28

Rapid and continuous delivery of useful software leads to customer satisfaction.
Customers, developers and testers constantly interact with each other.
Working software is delivered frequently - weeks instead of months.
Software can be easily adapted to changing circumstances - even late changes to requirements can be implemented.

Question 29

What are the disadvantages of the agile method of software development?

Answer 29

Lack of emphasis on design and documentation.
Project could fail to deliver if the customer isn’t clear on what they want.
Not suitable for novice programmers as they need to make good decisions quickly and independently.

Question 30

When would the agile method be used?

Answer 30

For small incremental changes that can be made quickly and cheaply. Good for expanding or developing businesses where a user needs are continually changing.