Model Based Testing课件.ppt

Model Based Testing
Property Checking for Real
Overview
Introduction
Testing
Formal methods and Testing
Formal Testing
Framework
Pre/post-condition program testing
Transition system testing
ioco test theory
a test tool
an application: "Rekeningrijden"
Conclusions
2
Overview
Introduction
Testing
Formal methods and Testing
Formal Testing
Framework
Pre/post-condition program testing
Transition system testing
ioco test theory
a test tool
an application: "Rekeningrijden"
Conclusions
3
Testing
Testing:
to check the quality of an objectby performing experimentsin a controlled way. a specification
Software Testing :testing the quality of a software product
m
n
n+m
tester
IUT
4
Paradox of Software Testing
Testing is:
important
much practiced
30% - 50% of project effort
expensive
time critical
not constructive(but sadistic?)
But also:
ad-hoc, manual, error-prone
hardly theory / research
no attention in curricula
not cool :“if you’re a bad programmer you might be a tester”
Attitude is changing:
more awareness
more professional
Improvements possiblewith formal methods !
?
5
Types of Testing
unit
integration
system
performance
robustness
functional behaviour
white box
black box
Level of detail
Accessibility
Characteristics
usability
reliability
module
stress
6
Testing
IUT
specificationproperty
IUTcorrect .specification
tester
pass fail
test cases
scenarios
7
Overview
Introduction
Testing
Formal methods and Testing
Formal Testing
Framework
Pre/post-condition program testing
Transition system testing
ioco test theory
a test tool
an application: "Rekeningrijden"
Conclusions
8
Formal methods:
proving properties
research
sound theories
“clean”
Testing :
trial & error
practice
heuristics
“dirty hands”
Testing & Formal MethodsA Perfect Couple ?
“Testing is not necessary after formal verification”
“Testing can only detect the presence of errors, not their absence”
“Formal methods are toys for boys”
“Formal me