Appendix
B:
Nonmandatory guidelines for certification/validation of safety systems
for presence sensing device initiation of mechanical power presses
Objectives
This Appendix provides employers, manufacturers, and their representatives,
with nonmandatory guidelines for use in developing certification
documents. Employers and manufacturers are encouraged to recommend
other approaches if there is a potential for improving safety
and reducing cost. The guidelines apply to certification/validation
activity from design evaluation through the completion of the
installation test and the annual recertification/revalidation
tests.
General Guidelines
A. The certification/validation process should confirm that hazards
identified by hazard analysis, (HA), failure mode effect analysis
(FMEA), and other system analyses have been eliminated by design
or reduced to an acceptable level through the use of appropriate
design features, safety devices, warning devices, or special procedures.
The certification/validation process should also confirm that
residual hazards identified by operational analysis are addressed
by warning, labeling safety instructions or other appropriate
means.
B. The objective of the certification/validation program is to
demonstrate and document that the system satisfies specification
and operational requirements for safe operations.
Quality Control
The safety attributes of a certified/validated PSDI safety system
are more likely to be maintained if the quality of the system
and its parts, components and subsystem is consistently controlled.
Each manufacturer supplying parts, components, subsystems, and
assemblies needs to maintain the quality of the product, and each
employer needs to maintain the system in a non-degraded condition.
Analysis Guidelines
A. Certification/validation of hardware design below the system
level should be accomplished by test and/or analysis.
B. Analytical methods may be used in lieu of, in combination with,
or in support of tests to satisfy specification requirements.
C. Analyses may be used for certification/validation when existing
data are available or when test is not feasible.
D. Similarity analysis may be used in lieu of tests where it can
be shown that the article is similar in design, manufacturing
process, and quality control to another article that was previously
certified/validated in accordance with equivalent or more stringent
criteria. If previous design, history and application are considered
to be similar, but not equal to or more exacting than earlier
experiences, the additional or partial certification/validation
tests should concentrate on the areas of changed or increased
requirements.
Analysis Reports
The analysis reports should identify: (1) The basis for the analysis;
(2) the hardware or software items analyzed; (3) conclusions;
(4) safety factors; and (5) limit of the analysis. The assumptions
made during the analysis should be clearly stated and a description
of the effects of these assumptions on the conclusions and limits
should be included.
Certification/validation by similarity analysis reports should
identify, in addition to the above, application of the part, component
or subsystem for which certification/validation is being sought
as well as data from previous usage establishing adequacy of the
item. Similarity analysis should not be accepted when the internal
and external stresses on the item being certified/validated are
not defined.
Usage experience should also include failure data supporting adequacy
of the design.
[53 FR 8360, Mar. 14, 1988]