1.2.3 - Software Development

Question 1

Software definition

Answer 1

Programs that run on a computer system - can be categorised as application or system

Question 2

5 software development stages

Answer 2

Analysis
Design
Implementation
Evaluation
Maintenance

Question 3

Analysis description

Answer 3

Information gathered about current system and what the new system needs to do
- interviews with users
- questionnaires
- observe current systems
- look at existing documentation
Document produced that defines what the system will do

Question 4

Design description

Answer 4

A description of the type/format/validations on data
Database design
How the data will be processed
How the software will be tested

Question 5

Implementation description

Answer 5

Coding and testing software
Writing user and technical documentation
Installing software for user
Testing

Question 6

4 types of testing

Answer 6

Black box testing
White box testing
Alpha testing
Beta testing

Question 7

Black box testing description

Answer 7

Carried out independently of code, checks that ALL types of valid input give a valid output and that invalid inputs do not error

Question 8

White box testing

Answer 8

Tests each path through the code at least once checking that it does the right thing

Question 9

Alpha testing description

Answer 9

Carried out by in-house team and user to reveal any missing requirements

Question 10

Beta testing description

Answer 10

Software given to a number of potential users who will report any faults - often to check the software is user-friendly

Question 11

Evaluation description

Answer 11

Software is checked to make sure it does everything required in document from analysis

Question 12

Three types of maintenance

Answer 12

Corrective
Adaptive
Perfective

Question 13

Corrective maintenance

Answer 13

Fixing bugs that have been found

Question 14

Adaptive maintenance

Answer 14

Changing based on the user’s changing needs

Question 15

Perfective maintenance

Answer 15

Improvements that are unnecessary but will improve experience

Question 16

5 development methodologies

Answer 16

Waterfall lifecycle
Agile
Extreme programming
Spiral model
Rapid application development

Question 17

Waterfall lifecycle description

Answer 17

Each stage is completed before the next one is begun

Question 18

Waterfall lifecycle advantages

Answer 18

Simple to understand and use
Stages are self-contained
Works well for small projects with well understood and fixed requirements

Question 19

Waterfall lifecycle disadvantages

Answer 19

Minimal user involvement
No working software produced until late
Customer does not see end product until completed
Any change often means restarting

Question 20

Waterfall lifecycle uses

Answer 20

Projects where:
- requirements are clear and fixed
- technology well understood
- short

Question 21

Spiral model description

Answer 21

Four steps (analysis, design, implementation, evaluation) completed repeatedly until software meets requirements. Then maintenance happens
Each loop develops a prototype

Question 22

Spiral model advantages

Answer 22

Easy to manage
Software produced early
Lots of user feedback at each prototype
End result fits requirements better

Question 23

Spiral model disadvantages

Answer 23

Time-consuming getting feedback every prototype
More costly due to time
Not suitable for smaller projects

Question 24

Spiral model uses

Answer 24

Projects where:
- unsure of needs
- requirements are complex
- large projects
- medium to high-risk

Question 25

Agile model description

Answer 25

Rapid incremental prototyping Each version builds on previous functionality and thoroughly tested

Question 26

Agile model advantages

Answer 26

Minimal planning required Rapid delivery of useful software Constant user input Easily adapted for changes

Question 27

Agile model disadvantages

Answer 27

Lack of documentation Not suitable for novice programmers - too fast Project can fail if customer does not give good input

Question 28

Agile model uses

Answer 28

Projects where - New changes need to be made - user's needs are constantly changing

Question 29

Extreme programming description

Answer 29

Agile methodology with very short cycles, intended to improve productivity and responsiveness to customer requirements changing

Question 30

Rapid application development description

Answer 30

Workshops and focus groups rather than formal documents Prototyping used 'Good enough' solution found as strict time frame Components reused whenever possible

Question 31

Issues with large projects

Answer 31

Personnel changes Requirements changing Technology advances Cost

Question 32

Algorithm definition

Answer 32

Set of instructions to solve a problem or complete a task in a finite number of steps

Question 33

Features of good algorithms

Answer 33

Correct output for all valid inputs Allows for invalid inputs Must terminate Efficient Readbale

Question 34

Features of good programs

Answer 34

Comments Consistent standard for identifiers Properly indented Modules perform single task Module no longer than a page

Question 35

Method of following algorithms

Answer 35

Trace table