Techno Savy

In automotive functional safety, identifying hazardous event due to a vehicle system failure is a important step. This step will help in highlighting the functional misbehavior due to system failure can cause undesired reaction that can be as bad as fatal. Such functions are to be ensured in a minimal operational state if failure happened to avoid such undesired event happened on road.

ISO26262 provides a methodology to perform this above step in a systematic way. This methodology is called HARA which stands for Hazard analysis and risk assessment. As the name implies, this method will analyze the hazard, evaluate the risk and helps in finalizing a safe state that reduces or mitigates this risk to a considerable level.

This analysis is performed by the complete product owner for which functional safety has to be applied or to be achieved. In case of automotive, OEM or vehicle manufacturers will perform this analysis since OEM know the complete overview of the item.

Item Definition

In simple words, Item can be anything which the end user will buy and use for his day to day activities.

Item Definition will have following information and describes the implementation of the item to achieve required functions.
1. Inputs
2. Outputs
3. funtional processing
4. Communication interface etc.

Inputs to perform HARA
–> Item Definition
–> Environment in which the item will be used
–> List of different situations the item will be used
–> List of functions of the item

Outputs of HARA
–> Safety goal for the functions
–> Safe state assocaited to the safety goal
–> ASIL level
–> FTTI

In my next post, We will see more detaily about how to perform the analysis and get the required outputs.