Transcript Transparency Masters for Software Engineering: A

Chapter 18
Software Testing Strategies
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
1
Testing Strategy
unit test
system
test
integration
test
validation
test
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
2
Unit Testing
module
to be
tested
results
software
engineer
test cases
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
3
Unit Testing
module
to be
tested
interface
local data structures
boundary conditions
independent paths
error handling paths
test cases
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
4
Unit Test Environment
driver
interface
local data structures
Module
boundary conditions
independent paths
error handling paths
stub
stub
test cases
RESULTS
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
5
Integration Testing Strategies
Options:
• the “big bang” approach
• an incremental construction strategy
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
6
Top Down Integration
A
B
F
top module is tested with
stubs
G
stubs are replaced one at
a time, "depth first"
C
as new modules are integrated,
some subset of tests is re-run
D
E
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
7
Bottom-Up Integration
A
B
G
drivers are replaced one at a
time, "depth first"
C
D
F
E
worker modules are grouped into
builds and integrated
cluster
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
8
Sandwich Testing
A
B
F
Top modules are
tested with stubs
G
C
D
E
Worker modules are grouped into
builds and integrated
cluster
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
9
High Order Testing
validation test
system test
alpha and beta test
other specialized testing
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
10
Debugging:
A Diagnostic Process
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
11
The Debugging Process
test cases
new test
regression cases
tests
suspected
causes
corrections
results
Debugging
identified
causes
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
12
Debugging Effort
time required
to correct the error
and conduct
regression tests
time required
to diagnose the
symptom and
determine the
cause
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
13
Symptoms & Causes
symptom and cause may be
geographically separated
symptom may disappear when
another problem is fixed
cause may be due to a
combination of non-errors
cause may be due to a system
or compiler error
symptom
cause
cause may be due to
assumptions that everyone
believes
symptom may be intermittent
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
14
Consequences of Bugs
infectious
damage
catastrophic
extreme
serious
disturbing
mild
annoying
Bug Type
Bug Categories: function-related bugs,
system-related bugs, data bugs, coding bugs,
design bugs, documentation bugs, standards
violations, etc.
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
15
Debugging Techniques
brute force / testing
backtracking
induction
deduction
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
16
Debugging: Final Thoughts
1. Don't run off half-cocked, think about the
symptom you're seeing.
2. Use tools (e.g., dynamic debugger) to gain
more insight.
3. If at an impasse, get help from someone else.
4. Be absolutely sure to conduct regression tests
when you do "fix" the bug.
These courseware materials are to be used in conjunction with Software Engineering: A Practitioner’s Approach, 5/e and are
provided with permission by R.S. Pressman & Associates, Inc., copyright © 1996, 2001
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