Automatic Generation of Conformance Tests from Message Sequence Charts

Over the past five years our group has developed a tool that automatically generates conformance test scripts from a combination of Message Sequence Charts (MSCs), specifying dynamic behaviour, and Protocol Data Units (PDUs), specifying data formats. This paper outlines how tests are derived from MSCs and PDU specifications, and summarises different test strategies. It describes the testing required to prove conformance of various MSC language features ranging from time constraints to MSC variables, in-line expressions and high-level MSCs. We cover test generation for both single process test scripting and concurrent test scripting, where a test is distributed across autonomous processes, co-ordinating through additional messaging. All of the above aspects have been implemented in our tool that is in widespread use across Motorola. Tool support has not only resulted in cycle-time benefits for test preparation, but quality improvement in the testing process, improved test coverage, and validation of requirements specification.