A dependability case construction approach based on dependability deviation analysis

As computer-based systems play an important role in our daily life, dependability assessment of these systems is of great significance. Simply combining the result of each dependability attribute could not reflect system dependability faithfully. Therefore, holistic methods to assess dependability are necessary. As a new and promising method which focused on demonstrating the dependability of product-specific system, structured assurance case model receives growing attention. Build a dependability case systematically and effectively is challenging work, particularly for systems which involves multi-contractor who have different responsibilities. In this paper, we proposed a new dependability case construction method to address the ownership problem of system dependability case which involves multiple contractors. Our method extends the existing Dependability Deviation Analysis with contractor's analysis and elicitation and integrates the contractor's information into the whole dependability argument architecture. We illustrate our contributions by application to a Train Control and Monitor System which preliminarily shows the effectiveness of our method.