The initial expression of requirements for a computer-based system is often informal and possibly vague. Requirements engineers need to examine this often incomplete and inconsistent brief expression of needs. Based on the available knowledge and expertise, assumptions are made and conclusions are deduced to transform this ‘rough sketch’ into more complete, consistent, and hence correct requirements. This paper addresses the question of how to characterize these properties in an evolutionary framework, and what relationships link these properties to a customer's view of correctness. Moreover, we describe in rigorous terms the different kinds of validation checks that must be performed on different parts of a requirements specification in order to ensure that errors (i.e. cases of inconsistency and incompleteness) are detected and marked as such, leading to better quality requirements.
['Didar Zowghi', 'Vincenzo Gervasi']
On the interplay between consistency, completeness, and correctness in requirements evolution