NEN EN 954-1 : 1997

Foreword
0 Introduction
1 Scope
2 Normative references
3 Definitions
4 General considerations
4.1 Safety objectives in the design
4.2 General strategy for design
4.3 Process for the selection and design of safety measures
4.4 Principles for ergonomic design
5 Characteristics of safety functions
6 Categories
6.1 General
6.2 Specifications of categories
6.3 Selection and combination of safety-related parts to
      different categories
7 Fault consideration
7.1 General
7.2 Fault exclusion
8 Validation
8.1 General
8.2 Validation plan
8.3 Validation by analysis
8.4 Validation by testing
8.5 Validation report
9 Maintenance
10 Information for use
Annexes
A (informative) Questionnaire for the design process
B (informative) Guidance for the selection of categories
C (informative) List of some significant faults and
      failures for various technologies
D (informative) Relationship between safety, reliability
      and availability for machinery
E (informative) Bibliography
ZA (informative) Clauses of this European Standard
      addressing essential requirements or other provisions
      of EU directives

Gives safety requirements and guidelines on the principles for the design of safety-related parts of control systems. Defines categories and gives characteristics of safety functions, including programmable systems for all machinery and for related protective devices. Applicable to all safety related parts of control systems whatever the type of energy used.