Design Validation & Integration
Testing
CS 3300
Colin Potts
V-model again
• Q: How & when can you
assess a design?
– Designs don’t run
•LHS -> RHS
– LHS = synthesis (1st)
– RHS = testing (last)
– LHS->RHS is test planning
(as early as possible)
• Design (modules and
interfaces) -> Integration
test plan
• Detailed design / module
spec. -> Unit test plan &
cases
Acceptance/
reqts validn.
Acceptance/
reqts validn.
Requirements
analysis
Requirements
analysis
System test/
design review
System test/
design review
Design
Design
Coding
Coding Unit testing/
review
Unit testing/
review
Terminology
• Integration Testing
– Testing of subsystems as a whole
– Units assumed to have been tested and passed
•Review
– Systematic examination of a design, usually by
a team
• Inspection
– Special kind of review
Integration testing
_Principle
–Individual program units may
work in isolation
–But may not work correctly
when integrated
_Localization of defects
–Defect may be manifested not
at source, but in a different
program unit
Ctrl
I' P' O'
JQR
M
defect here
failure
here
Interface errors
• Interface misuse
– A calling component calls another component and
makes an error in its use of its interface e.g. parameters
in the wrong order
• Interface misunderstanding
– A calling component embeds assumptions about the
behaviour of the called component which are incorrect
• Timing errors
– The called and the calling component operate at
different speeds and out-of-date information is accessed
Testing strategies
• Testing strategies are ways of approaching the
testing process
– Incremental testing of builds
– Usually combined in different parts of the system
• Examples (illustrations from Sommerville, 1995)
– Top-down testing
– Bottom-up testing
– Thread testing
– Stress testing
