JOTP-011
5 December 2014
APPENDIX A. BACKGROUND/RATIONALE
This document was developed within the international community and is written with references
to both U.S. and NATO test procedures to provide a framework for international procurement and
test programs. Table I2-1 (Appendix I, Annex 2) provides cross reference of similar national and
international test standards.
A1. INTRODUCTION.
This Appendix provides background information and rationale for the sample quantities and test
environments recommended by this document. Formal safety testing is required to establish test
data, which supports the issuance of the safety certification. The tests may indicate that limitations
or restrictions must be imposed when the safety certification is issued. These restrictions may be
imposed to limit exposure to certain environments (climatic, dynamic, electromagnetic, etc.), to
restrict methods of transportation, or to define special handling and operating procedures.
Generally, because of increased severity associated with safety testing, satisfactory performance
of the test item is not required. Poor performance after exposure to test environments may indicate
a need for further investigation.
A2. SAMPLE QUANTITIES AND STATISTICAL CONSIDERATIONS.
The sample size recommendations of this document are based on prior tests of similar weapons
and munitions, rather than strictly statistical considerations. Serious hazards such as warhead
detonation or rocket motor burst at launch are observed as binomial (pass or fail) events, but the
parameters that cause these events are unlikely to be so. For a simple binomial assessment, the
predicted low failure rate coupled with a requirement for high statistical confidence, the sample
sizes become very large, sometimes in excess of the eventual service population. This is not
practical; therefore, other approaches are required in combination with statistical methods to
estimate the residual safety margin based on measured parameters. For sequential environmental
testing, confidence is built by ensuring the test environment provides the maximum feasible
cumulative stress to the test items. Statistical methods are used to derive the test severities to
ensure as far as practicable they envelope the predicted environment. However, as stated above,
the final test quantities presented in this document are a compromise based upon the experience of
a large international community of subject matter experts.
A2.1 Performance Test Data.
As described above, successful performance tests (component and munition level) with and
without environmental exposure add confidence to the safety of the munition. Utilization of these
data effectively increases the total number of samples.
A2.2 Increased-Severity Testing.
In order to yield acceptable confidence in safety test results with a relatively small sample size,
increased-severity testing is prescribed in this document. The probability of munition failure
resulting in a hazardous condition is increased by testing under conditions, which are
A-1
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