Hazard Analysis and Risk Assessment according to ISO

1 The objective of the hazard analysis and risk assessment is to identify and to categorise the hazards that malfunctions in the item can trigger and to formulate the safety goals related to the prevention or mitigation of the 

ISO 26262 provides alternative approaches to enter the hazard and risk analysis  

A systematic distinction for the vehicle system (item), which also has to be examined in the context of a system houndaiy analysis, is necessary for both approaches. Generally, this is required beforehand as part of the definition of the considered vehicle system. However, if the vehicle system is already partially existent, the technical characteristics and their behavior need to be balanced with the new vehicle system characteristics and their behavior and the new functional stmcture should be defined. In real life there aren t really any new vehicle systems in the automotive industry. Even functions such as ACC, brake assistant or park assistant and new automated functions are enhancements or just electrifications or remote-control systems of existing vehicle systems. 

If now a new function (see Fig. 4.8 the green ellipse internal logical element ) is based on an existing system, the analysis of the existing system could be a challenge, due to missing specifications and unknown considered architecture it becomes quite complex. 

A function that can influence a brake system and steering under certain circumstances has to examine the impact of the function on these two systems in each driving situation and in each operating simation because eventually the steering or the brake could act as an acmator for the new function. Based on that fact new potential malfunctions can occur, which should be examined by hazard and risk analysis The previously implemented safely mechanisms of the system must not be restricted, override or invalidated by the new functions. This is why clear and complete information of the previously implemented safety mechanisms and their operating principle is necessary. 

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