IEC TS 63394-2023 PDF

Full title and description

St IEC TS 63394-2023 — Safety of machinery: Guidelines on functional safety of safety-related control systems. This Technical Specification provides guidance and additional requirements to support the application of IEC 62061 and ISO 13849‑1 for the design, development and integration of safety‑related control systems (SCS) and safety‑related parts of control systems (SRP/CS), and addresses specific topics such as rarely activated safety functions and failure‑rate calculations for non‑electronic technologies.

Abstract

IEC TS 63394:2023 offers sector‑specific guidance for machinery functional safety. It: (1) supplements IEC 62061 and ISO 13849‑1 without replacing them; (2) proposes a typical classification of safety functions and typical architectures used in machinery; (3) addresses modes of operation including rarely activated (high‑demand but infrequent) safety functions; and (4) provides additional information for deriving and evaluating probability of dangerous failure per hour (PFH) formulas for subsystems using non‑electronic technologies (for example using Weibull‑based approaches). The document considers all lifecycle phases of machinery functional safety and explicitly excludes low‑demand operation per IEC 61508 and the use of LOPA or BPCS per IEC 61511 as risk reduction measures.

General information

• Status: Published Technical Specification (IEC TS).
• Publication date: 22 February 2023.
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 13.110; 25.040.99; 29.020.
• Edition / version: Edition 1.0 (2023).
• Number of pages: 142 pages (IEC publication metadata).

Additional bibliographic metadata recorded with the publication include an ISBN and a stability date to 2027.

Scope

This Technical Specification gives practical guidance and specifies additional requirements for the application of IEC 62061 or ISO 13849‑1 in the machinery sector. It focuses on safety functions that are relevant to machinery boundary conditions, addresses architectures and modes of operation used for such safety functions, and provides methods to derive and evaluate PFH formulas for subsystems considering the technology used (electrical, mechanical, pneumatic, hydraulic or other non‑electronic technologies). It does not replace the normative requirements of IEC 62061 or ISO 13849‑1 and does not address low‑demand mode according to IEC 61508 nor LOPA/BPCS scenarios according to IEC 61511.

Key topics and requirements

• Guidance for applying IEC 62061 and ISO 13849‑1 specifically in machinery contexts.
• Classification of typical safety functions and consideration of typical architectures for safety‑related control systems.
• Treatment of rarely activated safety functions (high‑demand but infrequent operation) and related design considerations.
• Guidance and alternative calculation approaches for failure rates and PFH for non‑electronic technologies (including Weibull‑based considerations where exponential assumptions are not appropriate).
• Lifecycle considerations for SCS / SRP/CS from design through decommissioning.
• Explicit exclusions and limits: not intended for low‑demand modes per IEC 61508; does not incorporate LOPA or BPCS risk‑reduction frameworks from IEC 61511.

These topics are intended to help machine builders, safety engineers and integrators interpret and apply existing functional safety requirements in situations where sector‑specific guidance adds clarity.

Typical use and users

Primary users include machine manufacturers, functional safety engineers, control system designers, system integrators, conformity assessment bodies and notified/certification bodies. The TS is used when existing standards (IEC 62061, ISO 13849‑1) require interpretation in machinery‑specific contexts, when dealing with rarely activated safety functions, or when evaluating failure‑rate calculations for technologies that do not follow exponential failure distributions. Safety‑related procurement, risk assessments and design verification activities for machines commonly reference this Technical Specification.

Related standards

Key normative and normative‑adjacent documents to consult alongside IEC TS 63394: IEC 62061 (safety of machinery — functional safety of safety‑related electrical, electronic and programmable electronic control systems), ISO 13849‑1 (safety‑related parts of control systems — general principles), IEC 61508 (functional safety of electrical/electronic/programmable electronic safety‑related systems) and IEC 61511 (process industry safety instrumented systems) as well as ISO 12100 (general principles for risk assessment and risk reduction). IEC TS 63394 is explicitly positioned as guidance that supplements IEC 62061 and ISO 13849‑1.

Keywords

functional safety; safety‑related control system (SCS); SRP/CS; machinery safety; IEC 62061; ISO 13849‑1; PFH; failure rate; Weibull; rarely activated safety function; lifecycle; safety architecture.

FAQ

Q: What is this standard?

A: IEC TS 63394:2023 is a Technical Specification titled "Safety of machinery — Guidelines on functional safety of safety‑related control systems." It provides sector guidance to supplement IEC 62061 and ISO 13849‑1 for machinery.

Q: What does it cover?

A: It covers guidance on classification of safety functions, typical safety architectures, modes of operation (including rarely activated safety functions), approaches for PFH/failure‑rate calculations for non‑electronic technologies, and lifecycle considerations for SCS/SRP‑CS. It does not replace IEC 62061 or ISO 13849‑1 and excludes low‑demand modes under IEC 61508 and LOPA/BPCS risk‑reduction frameworks under IEC 61511.

Q: Who typically uses it?

A: Machine builders, control system designers, safety engineers, system integrators, conformity and certification bodies, and standards committees use the TS when applying functional safety requirements in machinery‑specific contexts.

Q: Is it current or superseded?

A: IEC TS 63394:2023 was published on 22 February 2023 as Edition 1.0 and is published as a current Technical Specification; IEC lists a stability date (the date until which the document is not expected to be revised) aligned to 2027. Users should check national adoptions or corrigenda in their country for any endorsed localized versions.

Q: Is it part of a series?

A: It is a stand‑alone Technical Specification in the machinery safety domain but is explicitly intended to be used in conjunction with the sector standards IEC 62061 and ISO 13849‑1 and with general risk‑assessment guidance such as ISO 12100.

Q: What are the key keywords?

A: Functional safety, safety‑related control system, PFH, rarely activated safety function, IEC 62061, ISO 13849‑1, Weibull, lifecycle, safety architecture.