I wrote this page because in my professional work I've seen a lot of confusion about what ASIL accuracy is and how to calculate it. With cars incorporating increasing levels of system diagnostics and driver assistance, understanding how to calculate accuracy of safety-critical specs is pretty important. I wrote it because the concept can be derived from first principles and so readily explained, but I had trouble finding references to share with colleagues and so there seemed to be a need. I see the feedback that this article is labeled as a stub and needs sources, and will try to improve it... so if anyone has specific requests for clarifications I would welcome more specific feedback.