The aim of requirements-based testing is to generate test cases from a set of requirements for a given system or piece of software. In this paper we propose a formal semantics for the generation of test cases from requirements by revising and extending the results presented in previous works (e.g.: [21, 20, 13]). We give a syntactic characterisation of our method, defined inductively over the syntax of LTL formulae, and prove that this characterisation is sound and complete, given some restrictions on the formulae that can be used to encode requirements. We provide various examples to show the applicability of our approach
