A Formalization Method to Process Structured Natural Language to Logic Expressions to Detect Redundant Specification and Test Statements

Automotive systems are constantly increasing in complexity and size. Beside the increase of requirements specifications and related test specification due to new systems and higher system interaction, we observe an increase of redundant specifications. As the predominant specification language (both for requirements and test cases) is still natural text, it is not easy to detect these redundancies. In principle, to detect these redundancies, each statement has to be compared to all others. This proves to be difficult because of number and informal expression of statements. In this paper we propose a solution to the problem of detecting redundant specification and test statements described in structured natural language. We propose a formalization process for requirements specification and test statements, allowing us to detect redundant statements and thus reduce the efforts for specification and validation. Specification Pattern Systems and Linear Temporal Logic provide the base for our process. We did evaluate the method in the context of Mercedes-Benz Passenger Car Development. The results show that for the investigated sample set of test statements, we could detect about 30% of test steps as redundant. This indicates the savings potential of our approach.