Hazards Analysis & Risks Assessment By Sebastien A. Daleyden Vincent M. Goussen Hazards Analysis & Risks Assessment • Importance of safety in design • Hazard analysis: What is it? • An useful engineer’s tool: Designsafe Importance of safety in design Unintentional injuries • Cost of $399 billion a year only in the USA; • Fifth leading cause of death; • Due to interaction between machines and their environment and the way people live and work Engineers should more think about the safety of the users... Importance of safety in design The main reasons why we should more care about safety are: Time Costs Competition International Influences Capturing knowledge Product liability Hazard analysis: What is it? Objectives: Tool for engineers and safety practitioners to • identify possible hazards, • provide an evaluation of the risks, • prompt alternative design solutions to mitigate or control the risks to an acceptable level. Hazard analysis: What is it? Hazard: Potentially dangerous condition, which is triggered by an event, called the cause of the hazard. Risk: hazard that is associated with a severity and a probability of occurrence. Hazard analysis: What is it? Hazard analysis: Identify all possible hazards potentially created by a product, process or application. Risk assessment: It is the next step after the collection of potential hazards. Risk in this context is the probability and severity of the hazard becoming reality. Hazard analysis: What is it? When performed: Before the design begins. Information used: Literature, Scenarios, Expert opinions, Personal experience. Hazard analysis: What is it? General risk assessment protocol : Establish Analysis Parameters Identify Hazards Assess Risks Derive Risk Rating Reduce Risks Verify Effectiveness Document Results Hazard analysis: What is it? Establish Analysis Parameters Identify Hazards Assess Risks Derive Risk Rating Reduce Risks Verify Effectiveness Document Results These parameters can be limits of the machine or design, limits on uses, limits on the scope of the analysis, or other limits. Hazard analysis: What is it? Establish Analysis Parameters Identify Hazards Assess Risks Derive Risk Rating Reduce Risks Verify Effectiveness Document Results The nature of this step lends itself to a team approach such as brainstorming. Hazard analysis: What is it? Establish Analysis Parameters Identify Hazards Assess Risks Derive Risk Rating Reduce Risks Verify Effectiveness Document Results Two risk factors are used: • severity of injury • probability of occurrence Hazard analysis: What is it? Establish Analysis Parameters Risk matrix: Severity Category Identify Hazards Assess Risks Derive Risk Rating Reduce Risks Verify Effectiveness Document Results Probability Level Catastrophic Critical Marginal Negligible Frequent High High Serious Serious Probable High High Serious Low Occasional High Serious Low Low Remote Serious Low Low Low Improbable Serious Low Low Low If the risk is determined to not be acceptable, it is necessary to reduce that risk by implementing protective measures. Hazard analysis: What is it? Establish Analysis Parameters Identify Hazards Remedy actions are taken to reduce risks following the hazard hierarchy: Assess Risks Derive Risk Rating Reduce Risks Verify Effectiveness Document Results • Eliminate hazards through the design Protect Warn the user Train the user(s) Personal protective equipment Hazard analysis: What is it? Establish Analysis Parameters Identify Hazards Assess Risks Derive Risk Rating Reduce Risks Verify Effectiveness Document Results This assessment verifies that the remedy actions have reduced the risks to an acceptable level. Hazard analysis: What is it? Establish Analysis Parameters Identify Hazards Assess Risks Derive Risk Rating Reduce Risks Verify Effectiveness Document Results The documentation can be added to a technical file for future use. Hazard analysis: What is it? When to stop: There is no zero risk, always some residual risk remains. If the residual risk is acceptable, then the risk assessment process is completed. Hazard analysis: What is it? Caution: Any hazard, which is not identified, will not be addressed by safety measures and will not be detecting during testing. Hazard not identified during this analysis can create substantial risk to users of the design. Hazard analysis: What is it? An efficient tool: A new computer tool, named Designsafe, specially designed to speed the hazard analysis process has become available. It uses a task-based method to ensure all hazards to users are identified. An useful engineers’ tool: Designsafe dse has developed a fast, easy-to-use tool for engineers and safety professionals to incorporate safety through design by: identifying hazards prompting engineers to think about hazards which they otherwise might overlook conducting a risk assessment for identified hazards reducing risks in a structured method preventing accidents and reducing liability An useful engineers’ tool: Designsafe what it is... an engineering tool for improving product designs and processes a systematic method for conducting a taskbased safety analysis a technique for eliminating and controlling hazards An useful engineers’ tool: Designsafe what it does... gives designers a quick and easy tool to evaluate safety issues through design permits quick assessment of engineer's change orders to safety issues assists design engineers in completing a safety analysis for their products/processes helps companies identify potential hazards and provides methods for elimination prioritizes design activities related to risk An useful engineers’ tool: Designsafe what are the benefits... helps prompt remedy actions for existing hazards can be employed at all stages of the life cycle of a design assists in obtaining the CE mark for assessing European markets can be printed for documentation or a technical file helps assure all hazards are addressed to completion An useful engineers’ tool: Designsafe what are the limits... It’s a guide, not an expert system; Poor inputs or incomplete data lead to poor results. What could be the next steps ? Fault Tree Analysis (FTA) • a powerful diagnostic tool for analyzing complex systems, • begins with selecting the “top event”, • repeating this process at successive levels using standardized symbols identifies primary and secondary faults. What could be the next steps ? Failure Modes and Effects Analysis identifies potential product modes which could lead to accidents, breaks down designs into components or subcomponents, then systematically evaluates the potential for and effects of individual failures, results of the analysis are used to evaluate and implement preventive measures to eliminate or control hazards.