Validation Against Actual Behavior: Still a Challenge for Testing Tools

A quality-driven approach to software development and testing demands that, ultimately, the requirements of stakeholders be validated against the actual behavior of an implementation under test (IUT). Current approaches and tools for testing fall into one of two categories: code-centric or model-centric. In this paper we review typical tools offered in each of these two categories, in order to establish the ability of such tools to support validation against actual behavior. We postulate that such support requires that test cases be both a) traceable back to the requirements of stakeholders and b) executed using an actual IUT in order to determine their outcome based on the actual behavior of an IUT. We observe that, in general, code-based testing tools fail to offer traceability between stakeholders' requirements and test cases. In contrast, in model-based testing, tests are generated from and traceable back to models, but they are typically disconnected from an actual IUT. Thus, we argue that validation against actual behavior remains a challenge for most existing code-centric and model-centric testing tools. We conclude by suggesting some essential functionality for a testing tool that could support the validation of the requirements of stakeholders against the actual behavior of an