According to my previous slide share, Introduction to software engineering, http://www.slideshare.net/ssuser45a683/introduction-to-software-engineering-48462625. I would like to expand further in part of software testing.
Software testing is vital, no less than software development. It can be said that software testing should be the same level as software development.
The content of this slide will discuss the meaning of software testing. The importance of software and concepts of software testing.
8. Software development life cycle
Analysis and design
Planing
Implementation
Testing
Deployment
9. What is software testing?
1.Testing is the process of demonstrating that errors
are not present.
2.The purpose of testing is to show that a program
performs its intended functions correctly.
3.Testing is the process of establishing confidence
that a program does what it is supposed to do.
10. What is software testing?
Testing is the process of executing a
program with the intent of finding
errors.
11. Terms for software failures
Defect
Fault
Problem
Error
Incident
Anomaly
Variance
Failure
Inconsistency
Feature
Bug
Etc.
12. Software bug: a formal definition
(1 of 5)
The software does not do something that
the product specification says it should
do.
13. Software bug: a formal definition
(2 of 5)
The software does something that the
product specification says it should not
do.
14. Software bug: a formal definition
(3 of 5)
The software does something that the
product specification does not mention.
15. Software bug: a formal definition
(4 of 5)
The software does not do something that
the product specification does not
mention but should.
16. Software bug: a formal definition
(5 of 5)
The software is difficult to understand,
hard to use, slow, or in the software
tester’s eyes will be viewed by the end
user as just plain not right.
17. Software bug: a formal definition
1.The software does not do something that the product specification says
it should do.
2.The software does something that the product specification says it
should not do.
3.The software does something that the product specification does not
mention.
4.The software does not do something that the product specification does
not mention but should.
5.The software is difficult to understand, hard to use, slow, or in the
software tester’s eyes will be viewed by the end user as just plain not
right.
22. To find bugs
To find them as early as possible
And to make sure they get fixed
The goal of a software tester
23. The challenge of software testing
Exhaustive testing is impractical.
24. Exhaustive testing is impractical
A simple function adds two 32 bit numbers and returns a result.
Assumption: we can execute 1,000 test cases per second
How long will it take to exhaustively test this function?
(Signed range 32 bits integer is -2,147,483,648 to 2,147,483,647 and unsigned: 0 to 4,294,967,295)
25. Exhaustive testing is impractical
A simple function adds two 32 bit numbers and returns a result.
Assumption: we can execute 1,000 test cases per second
How long will it take to exhaustively test this function?
Answer: 585 million years
2 (32+32)
/1000/60/60/24/365 = 584,942,417 years.
(Signed range 32 bits integer is -2,147,483,648 to 2,147,483,647 and unsigned: 0 to 4,294,967,295)
34. Quality is not equal to test
If it is not built right in the first place,
then it is never going to be right.
35. Quality is not equal to test
Quality is achieved by putting development and testing into a blender
and mixing them until one is indistinguishable from the other.