WG 4 - TC 56/WG 4

IEC 61907:2009 gives guidance on dependability engineering of communication networks. It establishes a generic framework for network dependability performance, provides a process for network dependability implementation, and presents criteria and methodology for network technology designs, performance evaluation, security consideration and quality of service measurement to achieve network dependability performance objectives. This standard is applicable to network equipment developers and suppliers, network integrators and providers of network service functions for planning, evaluation and implementation of network dependability.

Specifies procedures to compare two observed - failure rates; - failure intensities; - rates/intensities of relevant events. The procedures are used to determine whether an apparent difference between the two sets of observations can be considered statistically significant. Numerical methods and a graphical procedure are prescribed. Simple practical examples are provided to illustrate how the procedures can be applied.

Specifies procedures to test whether an observed value of: - failure rate; - failure intensity; - mean time to failure; - mean operating time between failures; complies with a given requirement. Three types of test plans are prescribed as follows: - sequential test plans; - time/failure terminated test plan; - fixed calendar time/failure terminated test plans. Cancels and replaces IEC 60605-7, published in 1978, and its amendment 1 (1990), of which its constitutes a technical revision.

Provides numerical methods to complement graphical techniques in performing a goodness-of-fit test for Weibull distributed times to failure and gives an approximate procedure to obtain confidence intervals for the parameters of the two-parameter Weibull distribution when these are estimated by maximum likelihood. Applicable whenever a random sample of items is subjected to a test of times to failure for the purpose of estimating measures of reliability performance of the population from which these items were drawn.

Specifies procedures to verify the assumption of a constant failure rate or constant failure intensity as defined in IEC 60050(191). These procedures are applicable whenever it is necessary to verify these assumptions. This may be due to a requirement or for the purpose of assessing the behaviour in time of the failure rate or the failure intensity.

Provides guidance on software life-cycle activities to achieve dependable software. The activities identified can be part of a dependability programme for a system or related to a product containing software. This guide is intended to support IEC 60300-3-6. This guide can be used by acquirers, suppliers, developers, operators or maintainers of software. This guide is intended for all project participants who develop or use systems or products containing software.