Inside the standardization jungle: IEC 62061 and ISO 13849-1, complementary or competing?

A milestone in the standardization of safety technology was the publication of the IEC 61508 series. Main purposes of this series was to provide a tool for the development and validation of complex electrical, electronic and programmable electronic systems and to be a guideline for the development of sector standards IEC 61508 is now the standard to follow for development and validation of complex systems. Many derived standards were published, but at least one did not introduce SIL as a classification parameter: ISO 13849-1. So much the worse, another standard with practically the same scope but using the "classical" SIL approach was published: IEC 62061. For manufacturers and users: a worst case scenario.