35.2. Risk Assessment and Hazard Identification

A high-level analysis to identify major failure points before deployment. Considers:

• Mechanical hazards (e.g., moving arms, sharp tools)
• Electrical hazards (short circuits, overloads)
• Software risks (unexpected behavior, AI learning failures)

Preliminary Hazard Analysis, or PHA, serves as an early step in the risk assessment process. The main goal of PHA is to pinpoint key areas where failures may occur prior to the actual deployment of a robotic system. At this stage, different categories of hazards are identified:

1. Mechanical Hazards: These include risks related to physical components, such as moving robotic arms or sharp tools that could injure operators or bystanders.
2. Electrical Hazards: These risks arise from the electrical systems within the robots. They might include short circuits or overloads that could cause malfunction or fire.
3. Software Risks: This aspect considers errors in coding, unexpected computational behaviors, and issues with artificial intelligence learning processes that might lead to incorrect actions by robots.

Identifying these hazards early allows project teams to develop strategies to mitigate risks and enhance safety before systems are actively used in the field.

Think of a PHA like preparing for a road trip. Before you leave, you check your car's essential systems: the brakes (mechanical hazards), ensure your battery is secure (electrical hazards), and verify your GPS works correctly (software risks). By identifying potential problems before starting, you can make adjustments to ensure a safe journey.

A structured method that identifies possible failure modes in each component, their consequences, and prioritizes them based on severity, occurrence, and detectability.

Failure Modes and Effects Analysis (FMEA) is a systematic approach used to identify potential failure points within individual components of a robotic system. The process involves three key steps:

1. Identification of Failure Modes: This refers to analyzing how each part of the robot could potentially fail. Each component is scrutinized to find all possible ways it might not operate as intended.
2. Assessment of Consequences: For every identified failure mode, the potential consequences are considered. This helps to evaluate how serious the impact of each failure could be.
3. Prioritization: After determining the severity of consequences, the possible failure modes are ranked based on three criteria - how severe they are (severity), how likely they are to occur (occurrence), and how easily they can be detected before causing harm (detectability). This prioritization allows teams to focus on addressing the most critical failure modes first.

Consider a hospital's operation room as an analogy for FMEA. Each medical device (like a heart monitor) is evaluated for how it might fail. What would happen if it stopped working? If it’s likely to happen and hard to detect, the hospital must prioritize repairs or updates to keep patients safe, just as engineers would prioritize robot component risks in FMEA.

Risk is evaluated on a matrix of severity vs. likelihood. Safety goals are defined using:

• ALARP (As Low As Reasonably Practicable)
• ISO standards for risk acceptance

The Risk Matrix is a tool used to assess and visualize risks by comparing the severity of potential consequences against the likelihood of those consequences occurring. The process involves:

1. Mapping Risks: In this matrix, one axis usually represents the severity (from minor to catastrophic), and the other axis represents the likelihood (from rare to almost certain). By placing risks on this matrix, engineers can quickly visualize which risks require more immediate attention.
2. Defining Safety Goals: Two concepts are primarily used in defining acceptable risk levels:
   • ALARP (As Low As Reasonably Practicable): This principle ensures that risks are reduced to the lowest level that can be reasonably achieved, balancing the investment of time and resources against the benefits of reducing risk.
   • ISO Standards for Risk Acceptance: These are established international standards that provide benchmarks for assessing risks systematically, ensuring compliance with global safety expectations. Understanding this allows project managers and engineers to establish safety measures and create robust protocols to minimize risks effectively.

Picture a fire drill in a school. The school needs to evaluate potential hazards (like the risk of fire) on its premises. They would assess how likely a fire could start (likelihood) and how serious it would be if it did (severity). If the fire risk is high and the consequences severe, they need to take immediate, reasonable actions to make the school safer, akin to applying the ALARP principle in risk assessments.

--