The Safety Handbook ABB Jokab - Automation Systems and Controls

Working method as specified inEN ISO 13849-1Step 1StartDetermine the system's scope(space, usage, time, environment)Risk assessmentRisk analysisIdentify risk sources(all work operations during the life cycle)Step 2Estimate the risk(determine PL rwith S, F and P)Evaluate the risk(is action required?)Has the risk beenadequatelyminimised?NoYesEndNoYesAre new risksgenerated?NoReduce the risk(redesign, use protection, information)Is the measuredependent on thecontrol system?YesRisk assessment and risk minimisationAccording to the Machinery Directive, the machine builder(anyone who builds or modifies a machine) is required toperform a risk assessment for the machine design and alsoinclude an assessment of all the work operations that needto be performed. The EN ISO 12100 standard (combinationof EN ISO 14121-1 and EN ISO 12100-1/-2) stipulatesthe requirements for the risk assessment of a machine. Itis this that EN ISO 13849-1 is based on, and a completedrisk assessment is a prerequisite for being able to workwith the standard.Step 1 – Risk assessmentA risk assessment begins with determining the scope ofthe machine. This includes the space that the machine andits operators need for all of its intended applications, andall operational stages throughout the machine’s life cycle.All risk sources must then be identified for all work operationsthroughout the machine’s life cycle.A risk estimation is made for each risk source, i.e. indicationof the degree of risk. According to EN ISO 13849-1 the riskis estimated using three factors: injury severity (S, severity),frequency of exposure to the risk (F, frequency) and thepossibility you have of avoiding or limiting the injury (P possibility).For each factor two options are given.Where theboundary between the two options lies is not specified in thestandard, but the following are common interpretations:S1S2F1F2P1P2bruises, abrasions, puncture wounds and minorcrushing injuriesskeletal injuries, amputations and deathless frequently than every two weeksmore often than every two weeksslow machine movements, plenty of space, lowpowerquick machine movements, crowded, high powerBy setting S, F and P for the risk, you will get the PL rPerformanceLevel (required) that is necessary for the risksource.Finally, the risk assessment includes a risk evaluationwhere you determine if the risk needs to be reduced or ifsufficient safety is ensured.1:12ABB