Abstract
Requirements defects have a major impact throughout the whole software lifecycle. Having a specific defects classification for requirements is important to analyse the root causes of problems, build checklists that support requirements reviews and to reduce risks associated with requirements problems. In our research we analyse several defects classifiers; select the ones applicable to requirements specifications, following rules to build defects taxonomies; and assess the classification validity in an experiment of requirements defects classification performed by graduate and undergraduate students. Not all subjects used the same type of defect to classify the same defect, which suggests that defects classification is not consensual. Considering our results we give recommendations to industry and other researchers on the design of classification schemes and treatment of classification results.

Abstract

Abstract
Formal verification techniques aim at formally proving the correctness of a computer program with respect to a formal specification, but the expertise and effort required for applying formal specification and verification techniques and scalability issues have limited their practical application. In recent years, the tremendous progress with SAT and SMT solvers enabled the construction of a new generation of tools that promise to make formal verification more accessible for software engineers, by automating most if not all of the verification process. The Dafny system is a prominent example of that trend. However, little evidence exists yet about its accessibility. To help fill this gap, we conducted a set of 10 case studies of developing verified implementations in Dafny of some real-world algorithms and data structures, to determine its accessibility for software engineers. We found that, on average, the amount of code written for specification and verification purposes is of the same order of magnitude as the traditional code written for implementation and testing purposes (ratio of 1.14) – an “overhead” that certainly pays off for high-integrity software. The performance of the Dafny verifier was impressive, with 2.4 proof obligations generated per line of code written, and 24 ms spent per proof obligation generated and verified, on average. However, we also found that the manual work needed in writing auxiliary verification code may be significant and difficult to predict and master. Hence, further automation and systematization of verification tasks are possible directions for future advances in the field. © 2023, IFIP International Federation for Information Processing.

Abstract

Abstract