such input data is a highly creative process that involves
deep understanding of input domains [7, page 152].
Descriptive rules for selecting test input data play a
significant role in software testing [8], where these rules
approximate the functionality of an AUT. For example, a rule
for an insurance application is that some customers will pose
a high insurance risk if these customers have one or more
prior insurance fraud convictions and deadbolt locks are not
installed on their premises. Computing insurance premium
may consume more resources for a customer with a highrisk
insurance record that matches this rule versus a customer
with an impeccable record, since processing this high-risk
customer record involves executing multiple computationally
expensive transactions against a database. Of course, we use
this example of an oversimplified rule to illustrate the idea.
Even though real-world systems exhibit much more complex
behavior, useful descriptive rules often enable testers to build
effective performance fault revealing test cases.