This part of ISO 13849 specifies a methodology and provides related guidance for the design and integration of safety-related parts of control systems (SRP/CS), including the design of software. This document specifies the characteristics needed to determine the performance level required of safety functions. This document applies to SRP/CS for high demand and continuous mode including their subsystems, regardless of the type of technology and energy (e.g. electrical, hydraulic, pneumatic, mechanical), for many kinds of machinery. The standard does not apply to low demand mode. This document does not specify the safety functions or required performance levels that are to be used in particular applications. This document does not give specific requirements for the design of products that are parts of SRP/CS. This document does not provide specific measures for security (e.g. physical, IT-security, cyber security) aspects. NOTE 1 – This document specifies a methodology for SRP/CS design without considering if certain machinery (e.g. mobile machinery) requires specific requirements. These specific requirements can be considered in a Type‑C standard. NOTE 2 – See IEC 61508 for low demand mode. NOTE 3 – See also ISO/TR 22100-4 for IT-security aspects and IEC/TR 63074 for security aspects.