Machinery   -   Maintainability and Reliability

IEC 60605-6:2007 Equipment Reliability Testing -Tests for the validity and estimation  of the constant failure rate  and constant failure intensity

This standard specifies procedures to verify the assumption of a constant failure rate or constant failure intensity, as defined in IEC 60050(191), and to identify patterns in the failure rate or intensity. These procedures are applicable whenever it is necessary to verify such assumptions. This may be due to a requirement or for the purpose of assessing any variation with time of the failure rate or failure intensity. 
The objectives of the methods specified in this standard are as follows: 
– to test whether the times to failure of non-repaired items are exponentially distributed, i.e. the failure rate is constant;
– to test whether the times between failures of repaired item(s)  have any time trend, i.e. the failure intensity does not exhibit an increasing or decreasing trend;
– to construct graphs that allow the patterns in the failure rate or failure intensity to be displayed, with a view to verifying whether they can be assumed constant, to estimate their values or to identify the nature of any departure from constancy

IEC 61124 2nd Ed 2007 Reliability testing – Compliance tests for constant failure rate and constant failure intensity

This standard specifies procedures to test whether an observed value of
– failure rate,
– failure intensity,
– mean time to failure (MTTF),
– mean operating time between failures (MTBF),
conforms to a given requirement.
It is assumed, except where otherwise stated, that during the accumulated test time, the times to failure or the operating times between failures are independent and identically exponentially distributed. This assumption implies that the failure rate or failure intensity is constant.
Four types of test plans are described as follows:
– truncated sequential tests;
– time/failure terminated tests;
– fixed calendar time terminated tests without replacement;
– combined test plans.

IEC 60706-2 Ed 2:2006 Maintainability of equipment –Maintainability requirements and studies during the design and development phase
This  part  of   IEC 60706 examines   the maintainability  requirements and related design and use parameter, and discusses some activities necessary to achieve the required maintainability characteristics and their relationship to planning of maintenance. It describes the general approach in reaching these objectives.

IEC 60706-5 provide guidance for the early consideration of testability aspects in design and development;


IEC 60300-3-3 Ed 2.0 Life cycle costing
the life cycle costs consist of many contributing elements, this standard particularly highlights the costs associated with dependability of the product.


IEC 60812 Ed 2.0 2006 Analysis techniques for system reliability – Procedure for failure mode  and effects analysis (FMEA) 
This   In ternational  Standard describes  Failure  Mode and Effects Analysis (FMEA) and Failure Mode, Effects and Criticality Analysis  (FMECA) , and gives guidance as to how  they may be applied to achieve various objectives by
− providing the procedural steps necessary to perform an analysis;
− identifying appropriate terms, assumptions, criticality measures, failure modes;
− defining basic principles;
− providing examples of the necessary worksheets or other tabular forms 


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