Preventing Omission of Key Evidence Fallacy in Process-Based Argumentations

摘要

Process-based argumentations argue that a safety-critical system has been developed in compliance with the development process defined in the standards and provide the evidence for certification of compliance. However, the process-based argumentations cannot ensure that the evidences are sufficient to support the claim. If the argumentations are insufficient (i.e., fallacious) they may result in a loss of confidence on system's safety. It is thus crucial to prevent or detect fallacies in the process-based argumentations. Currently, argumentations review process to detect fallacies largely depends on the reviewers' expertise, which is a labour-intensive and error prone task. This paper presents an approach that validates the process models (compliant with Process Engineering Metamodel 2.0), and prevent the occurrence of fallacy, specifically, omission of key evidence in process-based argumentations. If fallacies are detected in the process models, the approach develops the recommendations to resolve them; afterwards the process and/or safety engineers modify the process models based on the provided recommendations. Finally, the approach generates the safety argumentations (compliant with Structured Assurance Case Metamodel) from the modified process models by using model-driven engineering principles that are free from the fallacies. The applicability of the proposed approach is illustrated in the context of ECSS-E-ST-40C (Space engineering-Software) standard.