New international standard for dependability

Abstract

In 2015 International Electrotechnical Commission adopted a new international standard IEC 60050-192 that specifies the main terms in the field of dependability with their definitions. It was developed by IEC/TC 56 “Dependability" under control of TC 1 “Terminology" and forms Part 192 of International electrotechnical vocabulary. This standard substituted the previous similar standard IEC 60050-191 adopted in 1990. This article is dedicated to IEC 60050-192, acquaintance with which is required for all specialists in the field of dependability. The new standard is compared with the previous IEC 60050-191, and with the similar Russian GOST 27.002-89. In comparison with IEC 60050-191 the new standard contains the modified content and scope, with exclusion of the sections containing the terms related to the quality of services of telecommunication and electric power systems. Based on that, IEC 60050-192 is entitled just with one word “Dependability". Therefore, now it totally corresponds to its status of a horizontal (i.e. inter-industrial, basic) standard. Terminology in the field of dependability is given in respect to a technical item, with analysis of the definitions of this notion, probable structure of the item and the number of terms specifying the types of items. IEC 60050-192 gives a new definition for “dependability": the ability of an item to perform as and when required. This definition was discussed actively, among the IEC experts who took part in the standard development, and among Russian specialists as well. The cluster of features of dependability has also changed: availability, reliability, recoverability, maintainability and maintenance support performance, and in some cases durability, safety and security. A new notion here is “recoverability” defined as ability of an item to recover from a failure, without corrective maintenance. This paper describes the standard's sections dedicated to an item's states and time notions, failures and faults, maintenance and repair, dependability indices, testing, design or engineering, analysis and improvement of dependability. It introduces and explains the most important terms, specifies new terms that were added to the standard, and those excluded from it. The article pays attention to the fact that certain terms have no adequate Russian equivalents. Though the Russian and international dependability terminologies have much in common, there are still significant differences between them. It is explained by the fact that the standardization of dependability terminology in our country that started half a century ago developed for a long time in isolation form similar work world-wide. Due to such differences the creation of a new GOST to be harmonized with IEC 60050-192 is currently not possible. But nevertheless it is necessary to seek to a maximum possible convergence of the Russian and international terminologies.