Risk Assessment Methodology for Robots and Other Machines

Assessing risk has always played a vital role in the development and implementation of industrial machinery. Industrial robots, in particular, and other machinery are evolving, and therefore so are the needs and regulatory requirements for the identification and understanding of the risks involved in working with these machines. Thanks to the passage and enforcement of regulations governing the use of industrial machinery by organizations such as the Robotic Industry Association (RIA), Occupational Safety and Health Administration (OSHA), the American National Standards Institute (ANSI), and the International Organization for Standards (ISO), conducting risk assessments on robotic systems and other machinery are not just good practices, they are mandatory.

According to OSHA, machine guarding (29 CFR 1910.212) is often on OSHA’s top 10 most frequently cited standards.  Even though machine guarding is only one aspect of the risk assessment, it is usually the starting point for internal risk assessments to be conducted. While OSHA does have several regulatory standards covering machine safeguarding and risk assessment requirements, they typically rely on national consensus standards for more in-depth requirements for conducting risk assessments, and much more. These ANSI consensus standards outline the requirements for hazard identification for robots and other machinery.

Each piece of machinery and process has its own set of particular challenges and risks. Risk could be interpreted differently between similar pieces of equipment and processes depending on the exposure of employees, position of the equipment within the process line, even the equipment’s location within a facility. Understanding and assessing the risks of robots and other machinery is not an easy task. Taking into consideration the ever changing regulations covering these pieces of equipment, employee exposure to hazards, and the requirements of risk assessments themselves opens the door to interpretation and confusion. Therefore, as technology, industry, and regulation changes and improves, there is an apparent shift in the need for a more quantitative approach to assessing risk, as compared to qualitative risk assessments which could be interpreted differently from one day to the next.

For this reason, Conversion Technology Inc. (CTI) has developed a risk assessment methodology that is easy to use and can be implemented for each piece of machinery, including robots and Computer Numeric Control (CNC) machine. This risk assessment methodology is referred to as the APH Risk Assessment, named after the developers of the method, Adam and PH Haroz, from CTI.

The APH Risk Assessment methodology takes a quantitative approach by assigning numeric values to different aspects of hazards and risks like the likelihood that the hazard is to be present during the task or operation and how often the employee is exposed to the hazard. The APH Risk Assessment allows for an objective and pragmatic appraisal of the hazards and associated risks of a robot or piece of machinery. It also allows for a simple method for prioritizing the abatement schedule of the identified risks and hazards. With the numeric values designated for the different hazards and risks for the multitude of tasks and operations of machinery, we can calculate the Risk Level for each observed hazard using CTI’s formulation. Based on the Risk Level calculated, an associated Risk Rating (from low risk to unacceptable risk), Action Priority, and recommendations for improvement is provided.

By assigning numerical values to the risks, we are able to separate those risks and hazards that can be easily abated through safeguarding from those that may require changing administrative or engineering practices. Once recommendations are provided, a new Risk Level is calculated for the observations after the recommended safeguards are in place and administrative and engineering practices are implemented. The APH Risk Assessment Rating and Priority result table is as follows:

Regardless of the equipment in a facility and the safety equipment installed on robotic systems and other machinery, a risk assessment needs to be conducted that identifies the hazards of the equipment to ensure the safety of employees and to maintain compliance with OSHA and ANSI consensus standards. Contact CTI for more information on our quantitative risk assessment technique or to discuss conducting a complete robot risk assessment or a machine risk assessment of your facility.

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