Safety assurance at GM and using model management to support it

当一辆车被设计出来时，汽车制造商——原始设备制造商（OEM）——会尽一切努力确保这辆车的安全可靠。随着软件驱动的混合动力系统和高级驾驶员辅助系统的加入，车辆的复杂性不断增加，系统设计和安全流程的工作量和难度也相应增加。最近，车辆软件和/或物理设计上看似微小的变化导致了安全召回，因为不可预见的子系统相互作用降低了车辆的安全性和/或可靠性，达到了不可接受的水平。为了解决这些问题，oem及其供应商合作制定了ISO 26262道路车辆功能安全标准，该标准规定了流程及其输出，应作为系统、软件和安全流程的一部分，用于需要不同汽车安全完整性级别的车辆功能。随着oem和供应商努力与ISO 26262保持一致，一个日益重要的问题出现了：设计和安全保证工件何时可以安全地重复使用，以及何时必须重新制作过程和由此产生的工作产品？如果汽车公司想要保持竞争力，并能够以公众愿意支付的购买成本提供更安全的汽车，它们就必须解决这个关键问题。为了帮助加拿大汽车行业解决这一问题，该项目将对设计和安全工件及其与明确的安全保证参数（称为（安全）保证案例）的关系进行建模。我们将提供模型管理流程和工具来分析模型，并确定设计变更对保证案例的影响。这将帮助工程师确定保证案例的哪些部分可以安全地重用，以及需要进一步的工程努力来证明新系统是可接受的安全。这项工作将扩展到管理整个产品线的安全保证模型，以帮助原始设备制造商应对全球产品开发制造的现实。

When a vehicle is designed, the car maker - the Original Equipment Manufacturer (OEM) - makes every effortto ensure that the vehicle will be safe and reliable. As vehicles have increased in complexity with the additionof software-enabled hybrid powertrains and Advanced Driver Assistance Systems, the system design and safetyprocesses have had a corresponding increase in required effort and difficulty. Recently, seemingly minorincremental changes in the vehicle's software and/or physical design have resulted in safety recalls because ofunforeseen subsystem interactions that have reduced vehicle safety and/or reliability to unacceptable levels. Tohelp address these issues, OEMs and their suppliers collaborated to produce the standard ISO 26262 RoadVehicles - Functional Safety, which prescribes processes and their outputs that should be produced as part ofthe system, software and safety processes for vehicle features that require different Automotive Safety IntegrityLevels. As OEMs and suppliers strive to be consistent with ISO 26262, an increasingly important questionarises: when can design and safety assurance artefacts be safely reused and when do the processes and theresulting work products have to be redone? Automotive companies must address this key question if they wantto remain competitive and be able to deliver ever safer vehicles at a purchase cost that the public is willing topay. To help the Canadian automotive industry address this issue, this project will model the design and safetyartefacts and their relationships with explicit safety assurance arguments known as a (safety) assurance case.We will provide model management processes and tools to analyze the models and determine the impact of adesign change on the assurance case. This will help engineers determine which parts of the assurance case canbe safely reused and where it requires further engineering effort to demonstrate that the new system isacceptably safe. The work will be extended to manage models of safety assurance for entire product lines tohelp OEMs deal with the reality of manufacturing for global product development.