Software Development Life Cycle

Question 1

Define SDLC

Answer 1

A systematic process that structures the development of software to deliver a project.

Question 2

What is the difference between Verification and validation?

Answer 2

Verification - testing the software to ensure it functions like intended from the developers designs.
Validation - validated the software based on client requirements.

Question 3

Compare the waterfall and incremental schemes

Answer 3

Incremental over waterfall
-less costly when requirements are changed
-client feedback is continously incorporated
Waterfall over incremental
-Greater distinction between stages of development
-Known requirement means more robust code
-Little to no room for error (more likely to get it right the first time)

Question 4

Testing comes into what part of the SDLC?

Answer 4

verification and validation

Question 5

What does it mean to verify?

Answer 5

-ensuring the code produces the correct outputs from the inputs
-formatting code to make it readable and neat is helpful

Question 6

What does it mean to validate?

Answer 6

-ensuring the code meets the clients requirements by functioning according to the criteria
-functionality
-performance
-usability

Question 7

What are the three types of testing?

Answer 7

Component testing -
System testing - components integrated into a systems are tested
Customer testing - user testing in target environment which may reveal undetected bugs

Question 8

Define unit testing and give an example

Answer 8

-A unit may be a class or function
-Call the function with test argument
-Compare result to expected result and report back

Question 9

Define an edge case and give examples

Answer 9

unit test cases that are unexpected or rare
-Rare or old user platform
-Upper and lower limits of range
-heavy internet traffic

Question 10

Give examples of corner cases

Answer 10

Multiple conditions in action
-Testing an unusual input (e.g. empty list)

Question 11

What is useful in the edge testing code?

Answer 11

Using a docstring to explain what the programme should deliver

Question 12

Define system testing

Answer 12

components integrated to create a complete system that are tested to find any faults by developers
-checking components and units are compatible

Question 13

Define release testing

Answer 13

requirements based testing that focuses on performance, usage and scenario testing

Question 14

In terms of debugging, why is testing important?

Answer 14

testing reveals bugs in the operation code.
-bugs are high risk as they can cause finincial loss or even loss of life
-it is cost effective to identify bugs in the early stages of testing/code development

Question 15

How can we prevent bugs?

Answer 15

Code review and legibility
-Pair programming
-Defensive programming

Question 16

Define version control

Answer 16

A system that tracks changes to software base files over time

Question 17

How can primitive version control be enforced?

Answer 17

Consecutive file naming

Question 18

Give examples of version control systems (VCS)

Answer 18

Git:
-decentralised VCS, links can be used to access files
-Subversion
-Mercurial
-Perforce
-Microsoft Team foundation VC

Question 19

If there a multiple users on a VCS, how can users work offline?

Answer 19

By the use of local repositries, local changes are synced to the main VC server

Question 20

Give the advantages of VCS

Answer 20

-No permanent work connection needed
-Every local repositry has the latest version of code base
-Whole projects can be restored

Question 21

Summarise the waterfall method

Answer 21

Key distinct stages that are cascade from one to the other.
-SMART and risk managed
-Specification is frozen
-Used for systems that have a detailed upfront spec

Question 22

Summarise the incremental method

Answer 22

A cyclic method
-Agile
-Regular team meetings
-Continuous validation
-fluid specification
-urgent solutions are prioritised

Question 23

Describe agile

Answer 23

Agile is an iterative approach that emphasises flexibility and customer needs
-agile intends to minimise waste and maximise efficiency

Question 24

What are the 5 key principles of agile?

Answer 24

Customer involvement - customers should evaluate new iterations
Embrace change - expect system requirements to change
Incremental delivery - software is developed in increments where spec is changed at every step
Maintain simplicity - work to eliminate complications
People not process- skills of the developement team should be organised