  Rule-based policy and contract systems have rarely been studied in terms of
their software engineering properties. This is a serious omission, because in
rule-based policy or contract representation languages rules are being used as
a declarative programming language to formalize real-world decision logic and
create IS production systems upon. This paper adopts an SE methodology from
extreme programming, namely test driven development, and discusses how it can
be adapted to verification, validation and integrity testing (V&V&I) of policy
and contract specifications. Since, the test-driven approach focuses on the
behavioral aspects and the drawn conclusions instead of the structure of the
rule base and the causes of faults, it is independent of the complexity of the
rule language and the system under test and thus much easier to use and
understand for the rule engineer and the user.
