Canada

ISO 13849 – 1 Analysis — Part 7: Safety-Related Software

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General architecture model of software
This entry is part 7 of 9 in the series How to do a 13849 – 1 ana­lys­is

Safety-Related Soft­ware Up to this point, I have been dis­cuss­ing the basic pro­cesses used for the design of safety-related parts of con­trol sys­tems. The under­ly­ing assump­tion is that these tech­niques apply to the design of hard­ware used for safety pur­poses. The remain­ing ques­tion focuses on the design and devel­op­ment of safety-related soft­ware that runs on that […]

Canada

ISO 13849 – 1 Analysis — Part 6: CCF — Common Cause Failures

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This entry is part 6 of 9 in the series How to do a 13849 – 1 ana­lys­is

What is a Com­mon Cause Fail­ure? There are two sim­il­ar-sound­ing terms that people often get con­fused: Com­mon Cause Fail­ure (CCF) and Com­mon Mode Fail­ure. While these two types of fail­ures sound sim­il­ar, they are dif­fer­ent. A Com­mon Cause Fail­ure is a fail­ure in a sys­tem where two or more por­tions of the sys­tem fail at the same time from a single […]

Canada

ISO 13849 – 1 Analysis — Part 5: Diagnostic Coverage (DC)

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A graph showing the theoretical "bathtub curve" for product failure rate over the lifetime of the product.
This entry is part 5 of 9 in the series How to do a 13849 – 1 ana­lys­is

What is Dia­gnost­ic Cov­er­age? Under­stand­ing Dia­gnost­ic Cov­er­age (DC) as it is used in ISO 13849 – 1 [1] is crit­ic­al to ana­lys­ing the design of any safety func­tion assessed using this stand­ard. In case you missed a pre­vi­ous part of the series, you can read it here. In the last instal­ment of this series dis­cuss­ing MTTFD, I brought up the […]