ida Cer tification Ser vices

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1 e ida Cer tificatin Ser vices IEC Functinal Safety Assessment Prject: 377 Series Trip Valves Custmer: Fisher Cntrls Internatinal, LLC Marshalltwn, IA USA Cntract Number: Q11/ Reprt N.: EPM 11/ R002 Versin V1, Revisin R1, July 3, 2013 Jack Ga The dcument was prepared using best effrt. The authrs make n warranty f any kind and shall nt be liable in any event fr incidental r cnsequential damages in cnnectin with the applicatin f the dcument. All rights reserved.

2 Management summary This reprt summarizes the results f the functinal safety assessment accrding t IEC carried ut n the 377 Series Trip Valves. The functinal safety assessment perfrmed by exida cnsisted f the fllwing activities: - exida assessed the develpment prcess used by Fisher Cntrls Internatinal, LLC by an n-site audit and creatin f a safety case against the requirements f IEC exida perfrmed a detailed Failure Mdes, Effects, and Diagnstic Analysis (FMEDA) f the devices t dcument the hardware architecture and failure behavir. - exida reviewed field failure data t ensure that the FMEDA analysis was cmplete. - exida reviewed the manufacturing quality system in use at Fisher Cntrls Internatinal, LLC. The functinal safety assessment was perfrmed t the requirements f IEC 61508: ed2, 2010, SIL 3 fr mechanical cmpnents. A full IEC Safety Case was prepared, using the exida SafetyCaseDB tl, and used as the primary audit tl. Hardware prcess requirements and all assciated dcumentatin were reviewed. Envirnmental test reprts were reviewed. Als the user dcumentatin (safety manual) was reviewed. Sme areas f imprvement were identified in the design prcess and the design prcedures were upgraded during the prject. Hwever because f the lw cmplexity f the prducts and the prven in use design, Fisher Cntrls Internatinal, LLC was able t demnstrate that the bjectives f the standard have been met. The results f the Functinal Safety Assessment can be summarized as: The Fisher Cntrls Internatinal, LLC 377 Series Trip Valves were fund t meet the requirements f IEC fr up t SIL 3 (SIL 3 Capable). The PFD AVG and architectural cnstraint requirements f the standard must be verified fr each element f the safety functin. The manufacturer will be entitled t use the Functinal Safety Lg. The manufacturer may use the mark: T-023 V2R1 Page 2 f 19

3 Table f Cntents Management summary Purpse and Scpe Prject management exida Rles f the parties invlved Standards / Literature used Reference dcuments Dcumentatin prvided by Fisher Cntrls Internatinal, LLC Dcumentatin generated by exida Prduct Descriptins IEC Functinal Safety Assessment Methdlgy Assessment level Prduct Mdificatins Results f the IEC Functinal Safety Assessment Open Issues Lifecycle Activities and Fault Avidance Measures Functinal Safety Management Safety Requirements Specificatin and Architecture Design Hardware Design Validatin Verificatin Prven In Use Mdificatins User dcumentatin Hardware Assessment Terms and Definitins Status f the Dcument Liability Releases Future Enhancements Release Signatures T-023 V2R1 Page 3 f 19

4 1 Purpse and Scpe This dcument shall describe the results f the IEC functinal safety assessment f the Fisher Cntrls Internatinal, LLC: 377 Series Trip Valves by exida accrding t the requirements f IEC 61508: ed2, The results f this prvides the safety instrumentatin engineer with the required failure data as per IEC / IEC and cnfidence that sufficient attentin has been given t systematic failures during the develpment prcess f the device. T-023 V2R1 Page 4 f 19

5 2 Prject management 2.1 exida exida is ne f the wrld s leading accredited Certificatin Bdies and knwledge cmpanies specializing in autmatin system safety and availability with ver 300 years f cumulative experience in functinal safety. Funded by several f the wrld s tp reliability and safety experts frm assessment rganizatins and manufacturers, exida is a glbal cmpany with ffices arund the wrld. exida ffers training, caching, prject riented system cnsulting services, safety lifecycle engineering tls, detailed prduct assurance, cyber-security and functinal safety certificatin, and a cllectin f n-line safety and reliability resurces. exida maintains a cmprehensive failure rate and failure mde database n prcess equipment. 2.2 Rles f the parties invlved Fisher Cntrls Internatinal, LLC exida exida Manufacturer f the 377 Series Trip Valves Perfrmed the hardware assessment Perfrmed the IEC Functinal Safety Assessment accrding. Fisher Cntrls Internatinal, LLC cntracted exida in June 2012 fr the IEC Functinal Safety Assessment f the abve mentined devices. 2.3 Standards / Literature used The services delivered by exida were perfrmed based n the fllwing standards / literature. [N1] IEC (Parts 1-7): 2010 Functinal Safety f Electrical/Electrnic/Prgrammable Electrnic Safety-Related Systems 2.4 Reference dcuments Dcumentatin prvided by Fisher Cntrls Internatinal, LLC [D1] 15B15.8; Issue 2 Rev D; 1/3/ B15.8 Internal Audit - Internal Audit Prcedure [D2] 15B84; Rev C; 24/8/ B84 Auditr / Lead Auditr Qualificatin [D3] [D4] 377 current rder & certificatin; 8/11/ Prduct Requirements; 11/11/ current rder & certificatin - Manufacture Order and Certificatin fr 377 Trip Valve 377 Prduct Requirements - Original Prduct Requirements [D5] 4.05A; Rev 0; 25/8/ A - Crprate Quality System Dcument Cntrl [D6] 48a1042_g_1i_e; n/a; 48a1042_g_1i_e - Finalised versin f Example markup T-023 V2R1 Page 5 f 19

6 drawing fr a majr change [D7] 48A1042_MUG[1]; n/a; 48A1042_MUG[1] - Example markup drawing fr a majr change [D8] Training; 11/12/ Training Training Lg [D9] ag ; Rev 04; 21/5/2012 [D10] ASL fr ; n/a; [D11] Atex Fsp0703-V3; Rev 3; 21/5/2009 [D12] Atex FSP0807-V1.1; Rev 1.1; 28/3/2011 ag CSN-U001, CSN Business Prcess Glbal Supprt Guide ASL fr Supplier List f 377 & 4660 fr China facility Atex Fsp0703-V3 - EVALUATION OF SUPPLIER/ SUBCONTRACTOR Atex FSP0807-V1.1 - CONTROL OF NONCONFORMING PRODUCT [D13] Calibratin Recrd; 23/6/2010 Calibratin Recrd - Calibratin Recrd fr Tranductr PSI [D14] CAR Example; n/a; [D15] Custmer Supprt; 22/4/2010 [D16] Dcument List; 24/3/2011 [D17] ECRN IAR; Rev A; 4/5/2011 [D18] ECRN ; n/a; [D19] em_377x0; Rev K; 15/6/2011 [D20] em_377x1; Rev BD; 2/5/2012 [D21] em_377x2; Rev D; 2/5/2012 [D22] EP42; Rev A; 21/5/2009 [D23] ES 192; Rev AA; 30/3/2010 [D24] ES 192 Example; 17/1/2010 [D25] ES 235; Rev J; 29/9/2003 [D26] ES 238; Rev K; 17/1/2011 [D27] ES 250; Rev AY; 12/10/2011 [D28] ES 250 DB Example; N/A; 16/3/2011 [D29] ES 251; Rev E; 10/2/2010 [D30] ES 269; Rev A; 10/3/2010 [D31] ES102; Rev AB; 25/2/2011 CAR Example - Crrective Actin Request Example FCI - Custmer Supprt Netwrk Glbal Manual Dcument List - exida Dcument Checklist Cmplete ECRN IAR_Relcate ATEX Label in 2625X2 ECRN Sample ECRN em_377x0 - Engineering Master Index fr Type 377 Pilt Operated Trip Valve em_377x1 - Engineering Master fr Type 377 Pilt Operated Trip Valve (AL Cnstruectin) em_377x2- Engineering Master fr Type 377 Pilt Operated Trip Valve (SST Cnstruectin) EP42 - Prject Management Prcedure ES Design Change Prcedure ES 192 Example - Change Request/Order ES 235 Prduct Safety ES Technical Assessment Prcess ES Designated Engineer List ES 250 DB Example - Basic Search Example ES Instrument Engineering Prduct Develpment Prcess ES Prduct Develpment Prcess fr Safety Instrumented Systems ES102 - Prcedure fr Cntrl f Dcuments T-023 V2R1 Page 6 f 19

7 [D32] ES2; Rev EH; 2/5/2011 [D33] FGS 12G5; Rev D; 12/9/2011 [D34] FGS 15B15.10; Rev A; 12/4/2011 [D35] FGS 15B41; Rev A; 7/5/2003 [D36] FGS 15B82; Rev A; 9/5/2003 [D37] fgs12d94; Rev H; 4/1/2011 [D38] FGS15B15.6; Rev B; 22/11/2011 [D39] First Article Example; n/a; 31/8/2011 [D40] FMP Index; n/a; 9/11/2009 [D41] FROMEX; 6/8/2009 [D42] FTEP 1B1; Rev D; 8/7/1999 [D43] Impact Analysis Checklist; Rev L; 17/3/2011 [D44] IOM; D200319X012; 1/8/2012 [D45] ISO 9001; n/a; [D46] Prduct Bulletin; 62.3; 1/9/2004 [D47] QM; Iss 2 Rev F; 1/1/2012 [D48] Safety Manual; D103775X012; 26/6/2013 [D49] SM Review; 26/6/2013 [D50] SR Summary Reprt; n/a; 19/10/2009 [D51] SR578278_Evaluatin_cmbi ne; n/a; 29/4/2009 [D52] SRS; Rev 0.1; 12/6/2013 [D53] Training Recrd; n/a; [D54] Training Recrd Sample; n/a; [D55] YYGANN MRD; Rev 0.1; 6/5/2010 [D56] fgs 15b13.2; Rev c; 8/5/2012 ES2 - Methd f Revising Drawing and Other Engineering Dcuments FGS 12G5 - General Specificatin fr Type 377 Trip Valve FGS 15B Cntrl f Nncnfrming Prduct FGS 15B41 - Cntrl f Dcuments FGS 15B82 - Preventive Actin Prcedure fgs12d94 - Sample f Fisher General Specificatin FGS15B Crrective Actin Prcedure First Article Example - Sample First Article Evaluatin Reprt FMP Index - Equipment Inspectin Index FROMEX - Certificate f Registratin FROMEX, S.A. DE C.V. FTEP 1B1 - Calibratin Prcedure fr Pressure Measurement Equipment Impact Analysis Checklist - Draft IOM - IOM Manual Trip Valve ISO ISO 9001 Certificate Prduct Bulletin Trip Valve FCI - Quality Manual Safety Manual - Safety Manual fr Fisher 377 Trip Valve SM Review Trip Valve and 4660 High-Lw Pressure Pilt SR Summary Reprt - Sample cmpleted Service Request fllwing custmer cmplaint SR578278_Evaluatin_cmbine - Sample f Service Request Summary Reprt SRS - Safety Requirements Specificatin 377 Trip Valve Training Recrd - Training Recrd Summary Sample Training Recrd Sample - Exprted frm training recrd database n 12Dec2012 YYGANN MRD (Draft) - Marketing Requirements Dcument (Template) FGS15B Supplier Evaluatin T-023 V2R1 Page 7 f 19

8 [D57] Cmpetency Matrix; Rev A; 11/12/2013 AP IBU PD Cmpetency Matrix Dcumentatin generated by exida [R1] EME Q R001 V1R1 377 Series Trip Valve FMEDA Reprt, Aug 15, 2012 [R2] PIU; 1/7/2012 [R3] Q Emersn 377 & 4660 audit checklist_v1r2, Dec 19, 2012 [R4] Q _377 Trip Valve SafetyCaseDB IEC61508 R8, Jul 3, 2013 [R5] EPM Q R002 V1R1 377 Series Trip Valve Assessment Reprt, Jul 3, 2013 FMEDA reprt, 377 Series Trip Valves PIU - Prven In Use Analysis 377 Trip Valve IEC Site Audit Reprt, Fisher Cntrls Internatinal, LLC IEC SafetyCaseDB fr 377 Series Trip Valves IEC Functinal Safety Assessment, Fisher Cntrls Internatinal, LLC 377 Series Trip Valves (this reprt) T-023 V2R1 Page 8 f 19

9 3 Prduct Descriptins 377 Series Trip Valves descriptin: The 377 Series pressure-sensing trip valves are fr cntrl applicatins where a specific valve/actuatr actin is required when supply pressure falls belw a specific pint. When supply pressure falls belw the trip pint the trip valve causes the actuatr t fail up (377U), lck in the last psitin (377L), r fail dwn (377D). When the supply pressure rises abve the trip pint, the 377 Series trip valve autmatically resets, allwing the system t return t nrmal peratin. Figure 1 shws the 377U Cnfiguratin. Figure 1 377U Cnfiguratin T-023 V2R1 Page 9 f 19

10 Figure 2 shws the 377D Cnfiguratin. Figure 2 377D Cnfiguratin T-023 V2R1 Page 10 f 19

11 Figure 3 shws the 377L Cnfiguratin. Figure 3 377L Cnfiguratin The safety functin f the trip valve is t mve the assciated actuatr t the safe psitin within the safety time. T-023 V2R1 Page 11 f 19

12 4 IEC Functinal Safety Assessment The IEC Functinal Safety Assessment was perfrmed based n the infrmatin received frm Fisher Cntrls Internatinal, LLC and is dcumented in this reprt. 4.1 Methdlgy The full functinal safety assessment includes an assessment f all fault avidance and fault cntrl measures during hardware develpment and demnstrates full cmpliance with IEC t the end-user. The assessment cnsiders all requirements f IEC Any requirements that have been deemed nt applicable have been marked as such in the full Safety Case reprt, e.g. sftware develpment requirements fr a prduct with n sftware. The assessment als includes a review f existing manufacturing quality prcedures t ensure cmpliance t the quality requirements f IEC As part f the IEC functinal safety assessment the fllwing aspects have been reviewed: Develpment prcess, including: Functinal Safety Management, including training and cmpetence recrding, FSM planning, and cnfiguratin management Specificatin prcess, techniques and dcumentatin Design prcess, techniques and dcumentatin, including tls used Validatin activities, including develpment test prcedures, test plans and reprts, prductin test prcedures and dcumentatin Verificatin activities and dcumentatin Mdificatin prcess and dcumentatin Installatin, peratin, and maintenance requirements, including user dcumentatin Prduct design Manufacturing Quality System Hardware architecture and failure behavir, dcumented in a FMEDA The review f the develpment prcedures is described in sectin 5. The review f the prduct design is described in sectin Assessment level The 377 Series Trip Valves have been assessed per IEC t the fllwing levels: SIL 3 capability The develpment prcedures have been assessed as suitable fr use in applicatins with a maximum Safety Integrity Level f 3 (SIL3) accrding t IEC T-023 V2R1 Page 12 f 19

13 4.3 Prduct Mdificatins Fisher Cntrls Internatinal, LLC may make mdificatins t this prduct as needed. Mdificatins shall be classified int tw types: Type 1 Mdificatin: Changes requiring re-certificatin, which includes the re-design f safety functins r safety integrity functins. Type 2 Mdificatin: Changes allwed t be made by Fisher Cntrls Internatinal, LLC prvided that: A cmpetent persn frm Fisher Cntrls Internatinal, LLC apprves the mdificatins. The mdificatin dcumentatin listed belw is submitted prir t a renewal f the certificatin t exida fr review f the decisins made by the cmpetent persn in respect t the mdificatins made. List f all anmalies reprted List f all mdificatins cmpleted Safety impact analysis which shall indicate with respect t the mdificatin: The initiating prblem (e.g. results f rt cause analysis) The effect n the prduct / system The elements/cmpnents that are subject t the mdificatin The extent f any re-testing List f mdified dcumentatin Regressin test plans T-023 V2R1 Page 13 f 19

14 5 Results f the IEC Functinal Safety Assessment exida assessed the develpment prcess used by Fisher Cntrls Internatinal, LLC fr these prducts against the bjectives f IEC parts 1-7. The assessment was dne n-site at the Shenzhen facility n December 11-12, 2012 and dcumented in the SafetyCase [R4]. 5.1 Open Issues The verall prcess is strng and the designs have extensive prven field experience, sufficient fr SIL 3 capability. Sme areas f imprvement were identified in the design prcess and sme f the design prcedures and frms were upgraded during the prject. All f the imprvements were evaluated and included in the final versin f the SafetyCase. 5.2 Lifecycle Activities and Fault Avidance Measures Fisher Cntrls Internatinal, LLC has a defined prduct lifecycle prcess in place. This is dcumented in the Quality Management System Manual [D47] and varius Quality Prcedures. Prducts are typically rdered by a prduct cde r mdel designatin. A dcumented mdificatin prcess is cvered in the Design Change Prcedure [D23]. N sftware is part f the design and therefre any requirements specific frm IEC t sftware and sftware develpment d nt apply. The assessment investigated the cmpliance with IEC f the prcesses, prcedures and techniques as implemented fr prduct design and develpment. The investigatin was executed using subsets f the IEC requirements tailred t the SIL 3 wrk scpe f the develpment team. The defined prduct lifecycle prcess was mdified as a result f the audit which shwed sme areas fr imprvement. Hwever, given the simple nature f the safety functin and the extensive prven field experience fr existing prducts Fisher Cntrls Internatinal, LLC was able t demnstrate that the bjectives f the standard have been met. The result f the assessment can be summarized by the fllwing bservatins: The audited Fisher Cntrls Internatinal, LLC design and develpment prcess cmplies with the relevant managerial requirements f IEC SIL Functinal Safety Management The valves manufactured by Fisher Cntrls Internatinal, LLC are typically built per the mdel designatin cde. The basic designs are standardized, but each rder can have materials variatins. T-023 V2R1 Page 14 f 19

15 FSM Planning Fisher Cntrls Internatinal, LLC has a defined prcess in place fr prduct design and develpment. Required activities are specified alng with review and apprval requirements. This is dcumented in detail in prcedure ES 269, Prduct Develpment Prcess fr Safety Instrumented Systems. In additin prject management is defined by prcedure EP 42, Prject Management Prcess Descriptin. EP 42 describes the prject management respnsibilities, which include the creatin f a Prject Management Plan (PMP). The PMP is a radmap fr the prject. The 377 Series Trip Valves were designed at least 30 years ag and therefre did nt g thrugh the same prcedures that exist tday at Fisher Cntrls Internatinal, LLC Therefre, templates and sample dcuments were nt part f this review. The mdificatin prcess is described in ES 192, Engineering Change Request Prcedure. This prcess and the prcedures referenced therein fulfill the requirements f IEC with respect t functinal safety management fr a prduct with simple cmplexity and well defined safety functinality. Versin Cntrl ES 269 requires that design dcumentatin be maintained under versin cntrl. The PMP includes the cnfiguratin management plan. In additin prcedure 4.05A, Crprate Quality System Dcument Cntrl describes the revisin cntrl f the quality system dcuments. Training, Cmpetency recrding Sectin 6.2 f the Quality Manual addresses Resurce Management. The Human Resurce department maintains training recrds f educatin, experience, training and qualificatins fr all persnnel. Department heads are respnsible fr identifying and prviding the training needs fr their department as well as prficiency evaluatins. PepleSft is used t track perfrmance reviews and training needs. The prcedures and recrds were examined and fund up-t-date and sufficient. Fisher Cntrls Internatinal, LLC hired exida Cnsulting t be the independent assessr per IEC and t prvide specific IEC knwledge Safety Requirements Specificatin and Architecture Design A Safety Requirements Specificatin was develped fr the 377 Series Trip Valves, 377 SRS, Rev 0.1. The SRS defines the Functinal Safety requirements as well as the Envirnmental Cnditins. The primary functinality f the trip valve is fr cntrl applicatins where a specific valve/ actuatr actin required when supply pressure falls belw a specific pint. When supply pressure falls belw the trip pint, the trip valve cause the actuatr t fail up, lck in the last psitin, r fail dwn. When the supply pressure rises abve the trip pint, the 377 trip valve autmatically resets, allwing the system t return t nrmal peratin. As the 377 Series Trip Valves designs is simple and is based upn standard designs with extensive field histry, n semi-frmal methds are needed. General Design and testing methdlgy is dcumented and required as part f the design prcess. This meets SIL Hardware Design The design prcess is dcumented in ES 269, Prduct Develpment Prcess fr Safety Instrumented Systems. Items frm IEC , Table B.2 include bservance f guidelines and standards, prject management, dcumentatin (design utputs are dcumented per quality prcedures), structured design, use f well-tried cmpnents / materials, and cmputer-aided design tls. This meets SIL 3. T-023 V2R1 Page 15 f 19

16 5.2.4 Validatin Since the 377 Series Trip Valves were develped ver 30 years ag, it was determined thrugh the Prven in Use calculatin that the 377 Series Trip Valves are suitable fr use in SIL 3 applicatins. Since the Prven in Use calculatin was used t validate the 377 Series Trip Valves, actual develpment validatin dcumentatin was nt examined. A prductin Assembly and Test Plan, FGS 12G5, Rev D was reviewed. All 377 Series Trip Valves are subject t this test prcedure befre shipping. As the 377 Series Trip Valves is a purely mechanical device with a simple safety functin, there is n separate integratin testing necessary. The 377 Series Trip Valves perfrm nly 1 Safety Functin, which is extensively tested under varius cnditins during validatin testing Verificatin The develpment and verificatin activities are defined in ES 269, Prduct Develpment Prcess fr Safety Instrumented Systems. Fr each design phase the bjectives are stated, required input and utput dcuments and review activities. This meets SIL Prven In Use In additin t the Design Fault avidance techniques listed abve, a Prven in Use evaluatin was carried ut n the Fisher Cntrls Internatinal, LLC 377 Series Trip Valves. Shipment recrds were used t determine that the 377 Series Trip Valves have >200 millin perating hurs and they have demnstrated a field failure rate less than the failure rates indicated in the FMEDA reprts. This meets the requirements fr Prven In Use fr SIL Mdificatins Mdificatins are initiated per ES 192, Engineering Change Request Prcedure. Engineering changes are entered and tracked thrugh FISHWEB/Engineering & Technlgy/ECRN System. All changes are first reviewed and analyzed fr impact befre being apprved. Measures t verify and validate the change are develped fllwing the nrmal design prcess. This meets SIL User dcumentatin Fisher Cntrls Internatinal, LLC creates the fllwing user dcumentatin: Installatin, Operatin, Maintenance and Safety Manuals. The IOM was fund t cntain all f the required infrmatin fr nrmal installatin and maintenance. The Safety Manual prvides all the necessary infrmatin fr Safety System Installatins. The Safety Manual references the FMEDA reprts which are available and cntain the required failure rates, failure mdes, useful life, and suggested prf test infrmatin. Items frm IEC , Table B.4 include peratin and maintenance instructins, user friendliness, maintenance friendliness, prject management, dcumentatin, limited peratin pssibilities (377 Series Trip Valves perfrm well-defined actins) and peratin nly by skilled peratrs (peratrs familiar with type f valve, althugh this is partly the respnsibility f the enduser). This meets SIL Hardware Assessment T evaluate the hardware design f the 377 Series Trip Valves Failure Mdes, Effects, and Diagnstic Analysis s were perfrmed by exida. These are dcumented in [R1]. T-023 V2R1 Page 16 f 19

17 A Failure Mdes and Effects Analysis (FMEA) is a systematic way t identify and evaluate the effects f different cmpnent failure mdes, t determine what culd eliminate r reduce the chance f failure, and t dcument the system in cnsideratin. An FMEDA (Failure Mde Effect and Diagnstic Analysis) is an FMEA extensin. It cmbines standard FMEA techniques with extensin t identify nline diagnstics techniques and the failure mdes relevant t safety instrumented system design. Frm the FMEDA, failure rates are derived fr each imprtant failure categry. All failure rate analysis results and useful life limitatins are listed in the FMEDA reprt [R1]. Tables in the FMEDA reprt list these failure rates fr the 377 Series Trip Valves under a variety f applicatins. The failure rates listed are valid fr the useful life f the devices. Nte, as the 377 Series Trip Valves are nly ne part f a (sub)system, the SFF shuld be calculated fr the entire final element cmbinatin. These results must be cnsidered in cmbinatin with PFD AVG values f ther devices f a Safety Instrumented Functin (SIF) in rder t determine suitability fr a specific Safety Integrity Level (SIL). The architectural cnstraints requirements f IEC , Table 2 als need t be evaluated fr each final element applicatin. It is the end users respnsibility t cnfirm this fr each particular applicatin and t include all cmpnents f the final element in the calculatins. The analysis shws that the design f the 377 Series Trip Valves can meet the hardware requirements f IEC 61508, SIL 3 depending n the cmplete final element design. The Hardware Fault Tlerance, PFD AVG, and Safe Failure Fractin requirements f IEC must be verified fr each specific design. T-023 V2R1 Page 17 f 19

18 6 Terms and Definitins Fault tlerance FIT FMEDA HFT Lw demand mde PFD AVG PVST SFF SIF SIL SIS Type A element Type B element Ability f a functinal unit t cntinue t perfrm a required functin in the presence f faults r errrs (IEC , 3.6.3) Failure In Time (1x10-9 failures per hur) Failure Mde Effect and Diagnstic Analysis Hardware Fault Tlerance Mde, where the frequency f demands fr peratin made n a safetyrelated system is n greater than twice the prf test frequency. Average Prbability f Failure n Demand Partial Valve Strke Test It is assumed that the Partial Strke Testing, when perfrmed, is autmatically perfrmed at least an rder f magnitude mre frequent than the prf test, therefre the test can be assumed an autmatic diagnstic. Because f the autmatic diagnstic assumptin the Partial Valve Strke Testing als has an impact n the Safe Failure Fractin. Safe Failure Fractin summarizes the fractin f failures, which lead t a safe state and the fractin f failures which will be detected by diagnstic measures and lead t a defined safety actin. Safety Instrumented Functin Safety Integrity Level Safety Instrumented System Implementatin f ne r mre Safety Instrumented Functins. A SIS is cmpsed f any cmbinatin f sensr(s), lgic slver(s), and final element(s). Nn-Cmplex element (using discrete cmpnents); fr details see f IEC Cmplex element (using cmplex cmpnents such as micr cntrllers r prgrammable lgic); fr details see f IEC T-023 V2R1 Page 18 f 19

19 7 Status f the Dcument 7.1 Liability exida prepares reprts based n methds advcated in Internatinal standards. exida accepts n liability whatsever fr the use f this reprt r fr the crrectness f the standards n which the general calculatin methds are based. 7.2 Releases Versin: V1 Revisin: R1 Versin Histry: V1, R1: Released, July 3, 2013 V0, R1: Draft; February 5, 2013 Authrs: Jack Ga Review: V0, R1: Steven Clse; April 30, 2013 Release status: Released 7.3 Future Enhancements At request f client. 7.4 Release Signatures Jack Ga Yupeng, Safety Cnsultant Steven F. Clse, Safety Engineer T-023 V2R1 Page 19 f 19