Internal and External Views
• Any engineered product (and most other things)
can be tested in one of two ways:
– Knowing the specified function that a product
has been designed to perform, tests can be
conducted that demonstrate each function is
fully operational while at the same time
searching for errors in each function;
– Knowing the internal workings of a product,
tests can be conducted to ensure that "all gears
mesh," that is, internal operations are
performed according to specifications and all
internal components have been adequately
exercised.
CC20O7N Software Engineering 1
, Test Case Design
"Bugs lurk in corners
and congregate at
boundaries ..."
Boris Beizer
OBJECTIVE to uncover errors
CRITERIA in a complete manner
CONSTRAINT with a minimum of effort and time
CC20O7N Software Engineering 1
• Any engineered product (and most other things)
can be tested in one of two ways:
– Knowing the specified function that a product
has been designed to perform, tests can be
conducted that demonstrate each function is
fully operational while at the same time
searching for errors in each function;
– Knowing the internal workings of a product,
tests can be conducted to ensure that "all gears
mesh," that is, internal operations are
performed according to specifications and all
internal components have been adequately
exercised.
CC20O7N Software Engineering 1
, Test Case Design
"Bugs lurk in corners
and congregate at
boundaries ..."
Boris Beizer
OBJECTIVE to uncover errors
CRITERIA in a complete manner
CONSTRAINT with a minimum of effort and time
CC20O7N Software Engineering 1
