SRC Forum - Message Replies

Forum: Reliability & Maintainability Questions and Answers

Topic: Reliability & Maintainability Questions and Answers

Topic Posted by: Reliability & Maintainability Forum ( )
Organization: System Reliability Center
Date Posted: Mon Aug 31 12:47:36 US/Eastern 1998

Back to message list Topics List About this forum
Original Message:

Posted by: Jean-Marie CLOAREC ( )
Organization:LIGERON SA
Date posted: Thu Oct 4 5:57:56 US/Eastern 2001
Subject: def stan 00-56
Can anybody explain me the difference between "risk class" A, B, C, D and "claims limits" S1, S2, S3, S4 in DEF STAN 00-56 ? By the way I'm also searching failure rate for spark plug ! Thanks


Subject: Spark Plug Reliability
Reply Posted by: Bruce Dudley ( )
Organization: Reliability Analysis Center
Date Posted: Thu Oct 4 15:33:03 US/Eastern 2001
In the Reliability Analysis Center's Non-Electronic Parts Reliability Database (NPRD-95), I found a source of information relating to spark plugs. The handbook, on page 2-153, indicates that the failure rate of the spark plug is 3.68 failures per million hours. This rate does not consider the wearout side of the spark plug which under optimum conditions will only last 5,000 hours before failure.


Subject: 00-56
Reply Posted by: IC
Date Posted: Mon Oct 8 6:29:50 US/Eastern 2001
Risk Class is defined on page 25 of Def Stan 00-56 part 1 and S1, S2 etc is defined on page 27 of the same document and refers to safety integrity levels. The document can be downloaded free of charge from and then by clicking on the 00 - general data and scrolling down to 00-56 part 1. Hope this helps.

Back to message list Topics List About this forum
Reply to this message