In many cases, a new standard is introduced during a new product introduction or pilot project. Adopting and implementing a new standard is often met with many challenges, but studies have shown that the ISO 26262 standard integrates well with existing safety concepts in the automotive industry. Many companies are already realizing the benefits of identifying and evaluating risk related to electronic systems and applying appropriate testing throughout the product life cycle. The fundamental deliverables for ISO 26262 include development of a Safety Plan, creating Safety Goals, building and documenting your Safety Case, identifying the Safety Lifecycle and validation and verification of hardware and software systems, components and units. The ISO 26262 standard consists of 11 sections and hundreds of pages. It would be impossible to cover all the information in a brief review. Therefore, this page will focus on some key terms and definitions, along with the risk identification and analysis methods contained within the standard. The Eleven Parts of ISO 26262-1:
· Part 1: Vocabulary
· Part 2: Management of functional safety
· Part 3: Concept phase
· Part 4: Product development at the system level
· Part 5: Product development at the hardware level
· Part 6: Product development at the software level
· Part 7: Production and operation
· Part 8: Supporting processes
· Part 9: Automotive Safety Integrity Level (ASIL)-oriented and safety-oriented analyses
· Part 10: Guidelines on ISO 26262
· Part 11: Guideline on application of ISO 26262 to semiconductors
Application of the standard is focused on establishing safety goals and evaluating systems against those goals. The systems are evaluated at a vehicle level or “item” as per the standards terminology. Many people focus on the ASIL score, the method of ranking the possible hazards. Nevertheless, what we must remember is that the ISO 26262 standard is a goal-based standard. It is based on establishing safety goals, identifying risk and developing a plan to meet those goals.
If we step back and look at ISO 26262 as a whole, we note that the standard is about preventing harm to the operator or other individuals. Safety goals are the top-level safety requirements of an item or element. They precede development of the functional safety requirements for elimination or avoidance of unreasonable risk for a potential hazardous event. Safety goals should be expressed as functional objectives and not technical solutions. Next, we must determine our system’s dependability requirements based on the ASIL ratings for exposure, severity and controllability. However, ASILs are only one piece of the process in determining and verifying the required dependability of an item, element or component based on the risks and possible consequences resulting from a failure.
Before we go any further we need to look at some key terms used within the standard. In order to understand the standard, you must first learn the key terms and definitions used in application of the standard. Some of the key terms and definitions used include, but are not limited to, the following list:
· Item: Refers to a specific system or collection of systems that perform a particular function of the vehicle to which the ISO safety life cycle applies. The Item is the highest level identified in a process or system and is usually the initial point for development and analysis of the systems.
· Element: System of part of a hardware system, component or software code used within an E/E system.
· Component: One or more software units or hardware parts.
· Automotive Safety Integrity (ASIL): This helps identify the ISO requirements and safety measures to apply for avoiding unreasonable risk within the design and function of an item or element.
· Hazardous Event: The result of a vehicle-level hazard and operational situation of the vehicle that could potentially result in an accident and / or harm if not controlled by appropriate and timely driver action.
· Software Unit: The lowest level of the software that may be used for standalone testing.
· Hazard Analysis and Risk Assessment (HARA): Methodology used to identify and categorize possible hazardous events relating to items, develop safety goals and ASILs for development of prevention or mitigation of the potential hazards to avoid unreasonable risk.