& Quality Management
calculation with Siemens SN 29500
| MTBF-Calculation acc. to Standards
29500 has been developed and is maintained and updated by Siemens
company, with the latest issue 2011.
simple words, SN 29500 is a ready-for-use version of IEC 61709 (also
published by Siemens company).
It is a disadvantage that SN 29500 consists of 12
individual documents which have to be bought separately at a very high
total cost of about 600 €, but the
content of these 12 documents together is comparable with other
electronic reliability prediction standards, which usually cost not
more than 150 €.
12 documents have individual revisions, which makes it difficult to
name a formal SN 29500 revision. As of 2021, the latest issues
vary between 2004 to 2011.
electromechanical components like switches, relays, contactors and
connectors, Siemens SN 29500 offers the most sophisticated and
therefore the best calculation models among all electronic reliability
standards, while still keeping the required model parameters simple to
With respect to ICs, SN 29500 is the only standard to distinguish
between application types, for example operational amplifier, voltage
supply, regulator, switched regulator, etc.
In general however, SN 29500 is rather a simple standard with limited
component type coverage. Furthermore, it offers only a single
environment type, which is not even mentioned at all. Practical
experience suggests that the SN 29500 environment type is probably
avarage industrial environment.