Implementing the Data Safety Guidance

摘要

Data is everywhere. Data permeates our Safety Cases and even the way we form our Safety Cases. The Safety Critical Systems Club (SCSC) formed the Data Safety Initiative Working Group (DSIWG) in January 2013 to provide a forum for discussion across industries. The DSIWG has published the Data Safety Guidance, intended to be a starting point providing advice on how to conduct a data-focussed safety assessment. With data safety now making appearances in several standards (including Def Stan 00-055, IEC 61508, and DO178C), it is time to test the guidance. It is essential that we identify gaps in the definitions and usage of the guidance before progressing too far down one agreed way of thinking about data. Raytheon UK is currently developing a new Monopulse Secondary Surveillance Radar (MSSR) system, the Mk3 MSSR, with improved hardware performance using RF GaN technology and new functionality such as built-in Automatic Dependent Surveillance-Broadcast (ADS-B) and integrated GPS functionality. The Mk3 MSSR builds on the success of the Raytheon Mk2 MSSRs which are in service in 60 countries forming around 600 individual installations. With added functionality, there comes added data. More varied data types and uses of data will be transferred through the Mk3 MSSR compared with the previous generation Mk2 MSSR. The Data Safety Guidance (V1.3) published by the DSIWG has been applied to the Mk3 MSSR development project during the initial safety assessment, fully integrated within the safety assessment process. This paper summarises the results of the assessment, what it means for the Mk3 MSSR and Raytheon UK's customers, and how it can be used to improve the Data Safety Guidance.