EN 61649 EUROPEANSTANDARD NORMEEUROPEENNE EUROPAISCHENORM November 2008 ICS 03.120.01; 03.120.30 English version Weibull analysis (IEC 61649:2008) Analyse de Weibull Weibull-Analyse (CEI61649:2008) (IEC61649:2008) with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. CENELEC EuropeanCommitteeforElectrotechnical Standardization Comite Européen de Normalisation Electrotechnique Europaisches Komitee fur Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B -1050 Brussels ?2008CENELEC- All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref.No.EN 61649:2008 E EN61649:2008 - 2 - Foreword The text of document 56/1269/FDIS, future edition 2 ofIEC61649,preparedbyIECTC56 Dependability, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61649 on2008-10-01. The following dates were fixed: latestdatebywhichtheENhastobeimplemented at national level by publication of an identical national standard orby endorsement (dop) 2009-07-01 latest date by which the national standards conflicting withthe ENhavetobe withdrawn (dow) 2011-10-01 AnnexZAhas been added byCENELEC. Endorsement notice The text of the International Standard IEC 61649:2008 was approved by CENELEC as a European Standard without any modification. IEC 60300-1 NOTE Harmonized as EN 60300-1:2003 (not modified). IEC 60300-2 NOTE Harmonized as EN 60300-2:2004 (not modified). IEC 60300-3-1 NOTE Harmonized as EN 60300-3-1:2004 (not modified). IEC 60300-3-2 NOTE Harmonized as EN 60300-3-2:2005 (not modified). IEC 60300-3-4 NOTE Harmonized as EN 60300-3-4:2008 (not modified) IEC 61703 NOTE Harmonized as EN 61703:2002 (not modified) - 3 - EN61649:2008 Annex ZA (normative) Normative referencesto international publications with their corresponding Europeanpublications The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments)applies. NOTE When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC60050-191 1990 International Electrotechnical Vocabulary (IEV) - Chapter 191: Dependability and quality of service IEC60300-3-5 2001 Dependability management- Part 3-5: Application guide - Reliability test conditions and statistical test principles _ 1) IEC 61810-2 Electromechanical elementary relays - EN61810-2 2005 2) Part 2: Reliability ISO 2854 1976 Statistical interpretation of data - Techniques of estimation and tests relating to means and variances ISO3534-1 2006 Statistics -Vocabulary and symbols - Part 1: General statistical terms and terms used in probability 1) Undated reference. 2) Valid edition at date of issue. 61649@IEC:2008 -2 CONTENTS INTRODUCTION Scope 8 2 Normativereferences. Terms,definitions,abbreviationsandsymbols 3 .8 3.1Terms and definitions 3.2 Abbreviations 10 3.3 Symbols.... 4 Application of the techniques.. .11 5 The Weibull distribution. 11 5.1 The two-parameter Weibull distribution. 5.2 The three-parameter Weibull distribution. 13 6 Data considerations. 13 6.1 Data types... .13 6.2 Time to first