1、 Standard ANSI/AIA S-102.2.2-2009 Performance-Based System Reliability Modeling Requirements AIA standards are copyrighted by the American Institute of Aeronautics and Astronautics (AIA), 1801 Alexander Bel Drive, Reston, VA 20191-434 USA. Al rights reserved. AIA grants you a license as folows: The
2、right to download an electronic file of this AIA standard for storage on one computer for purposes of viewing, and/or printing one copy of the AIA standard for individual use. Neither the electronic file nor the hard copy print may be reproduced in any way. In adition, the electronic file may not be
3、 distributed elsewhere over computer networks or otherwise. The hard copy print may only be distributed to other employees for their internal use within your organization. ANSI/AIA S-102.2.2-209 American National Standard Performance-Based System Reliability Modeling Requirements Sponsored by Americ
4、an Institute of Aeronautics and Astronautics Approved 17 November 208 American National Standards Institute Abstract This Standard provides the basis for developing performance-based System Reliability Modeling to develop mathematical or simulation models to be used for making numerical aportionment
5、s and reliability predictions based on the reliability characteristics and functional interdependencies for al configured items required to perform the mision. The requirements for contractors, the planing and reporting neds, along with the analytical tols are established. The linkage of this Standa
6、rd to the other standards in the new family of performance-based Reliability and Maintainability (R plan the activities to achieve a level of R apraise the performance an R and identify the activities necesary to improve the performance of an R b) The description of system operating modes and enviro
7、nments versus the mision timeline; c) The listing of functional components versus reliability values; d) The maturity and confidence level of the reliability value for each functional component; e) The indentured graphical system reliability model; f) The indentured system reliability predictions by
8、 functional components, mision-critical system functions, and aplicable levels of mision suces; g) The identification of hardware or functional elements of the system that are not included in the system reliability model, along with rationale for each elements exclusion from the model. 5 Detailed Re
9、quirements The folowing detailed requirements pertain to the performance-based System Reliability Modeling proces defined in Anex B. ANSI/AIA S-102.2.2-2009 8 5.1 System Design Data Colection Prior to begining the evaluation of system failure modes, the contractor shal colect suficient system design
10、 information to define al aplicable functional and physical characteristics of the system, and the reliability atributes that fal within the analytical ground rules to be specified by the contractor (se reference 9). The system design information shal include al system levels, mision phases, and env
11、ironments, and al normal, degraded, and contingency system odes that are aplicable to each mision phase. If a Capability Level 3 or higher System Reliability Modeling proces is required, this information shal be entered in the System Reliability Modeling database to alow cros-referencing functional
12、components against oficial design drawings. At a minimum, the contractors analytical ground rules shal include the identification of reliability atributes for al functional and physical components that aply to the capability level of the System Reliability Modeling proces under contract. Suficient e
13、nginering information shal be colected to determine the maturity and confidence level of the reliability value(s) used for each functional or physical component. 5.2 System Reliability Modeling Proces A reliability model shal be developed and maintained for the system or the system of systems (SoS)
14、if required. At a minimum, the model shal be developed to the functional component level, shal define the physical components asociated with each functional component, shal define the probability of failure/suces or hazard rate for each physical component, and shal provide the probability of ocurenc
15、e for each unaceptable failure severity clasification as defined in Table 1. If a Capability Level 2 System Reliability Modeling proces is required, the model also shal provide the probability of ocurence for unanticipated failures3for each unaceptable failure severity clasification as defined in Ta
16、ble 1. Reliability modeling techniques shal be used that provide separate outputs for: (1) the predicted reliability of each mision critical function, and (2) predicted reliability of the system, i.e., colective reliability of the subsystems, asemblies, components, and parts. The reliability models
17、shal be traceable to and cros-referenced to the latest aproved system design schematics, drawings, and specifications. The redundancy switching devices, i.e., relays and circuits shal be clearly identified in the reliability model where aplicable. The nomenclature used to identify items in reliabili
18、ty model shal be consistent with that used in the latest aproved system design schematics, drawings, and specifications. The system reliability model shal be updated, as neded, with enginering information resulting from FMECA, tests, aproved design changes, environmental studies, operations planing,
19、 and field experience. If a Capability Level 3 System Reliability Modeling proces is required, the reliability modeling data products shal be compatible with the Product FMECA/Hazards Analysis database, and the functional component reliability models shal include software and software to hardware in
20、terfaces, as necesary, to predict system reliability. 5.2.1 System Reliability Predictions The contractor shal construct a system reliability model to depict the intended utilization of the elements of the system to achieve mision suces. The system reliability model shal consist of a graphical syste
21、m reliability model or RBD that shows al of the series-paralel functional paths that are required for sucesful system operation. Each reliability block in the RBD shal have a description that includes the item identification that is traceable to design schematics or drawings, the aplicable mision ti
22、me and environment, the operating modes of the item acros the mision timeline, the asumptions used to develop the reliability block, and the references for locating the simulation or mathematical expresions used to obtain reliability values. For this standard, a single reliability block shal be used
23、 to represent a simulation instruction set, an event tre diagram, a fault tre diagram, a Markov diagram4, or a probability truth table, al of which have varied degres of complexity, ranging from representing a single component to hundreds of components. 3For this standard, unanticipated system failu
24、res are operational anomalies that are not documented in reliability analyses or test anomaly reports. 4Markov diagram is the comon name given to graphical representations of state transition models. ANSI/AIA S-102.2.2-2009 9 Table 1 AIA S-102 Failure Severity Clasification Failure Severity Clasific
25、ation Failure Efect Description CATASTROPHIC failure would cause los of life or total disability to personel, or failure would cause identifiably catastrophic damage to system and repairs that are beyond the capability of the user or contractor to resolve the efects CRITICAL failure would cause seve
26、re disabling injury or severe ocupational ilnes to personel, or failure would cause identifiably critical damage to the system and extensive repairs to resolve the efects MARGINAL failure would cause minor injury or minor ocupational ilnes to personel, and those injuries or ilnes may require hospita
27、lization but they are not disabling, or failure would cause identifiably marginal damage to the system and aceptable level of repairs and downtime to resolve efects MINOR failure would cause minor injury or minor ocupational ilnes to personel, but those injuries or ilnes would not require hospitaliz
28、ation, or failure would cause identifiably minor damage to the system and minor repairs and short downtime to resolve efects NEGLIGIBLE failure would cause les than minor injury and no ocupational ilnes, or failure would cause negligible damage to the system and insignificant or no downtime to resol
29、ve efects, or failure is not credible 5.2.2 Storage/Dormant Reliability Predictions If required, the contractor shal construct a system reliability model to depict the intended periods of system storage or dormancy, which are non-operating time in the storage environment or mision environment, respe
30、ctively. The system reliability model shal consist of a graphical system reliability model or RBD that shows al of the functional paths in series, including system functions intended for redundancy or alternate modes of operation. For the special case where the system is in a quiescent mode, i.e., a
31、 portion of the system is operating while the remainder of the system is dormant, the system reliability model shal consists of an operating portion and a separate dormant portion. 5.3 System Reliability Modeling Database If a Capability Level 3 System Reliability Modeling proces is required, the co
32、ntractor shal establish a System Reliability Modeling database that contains the System Reliability Modeling data products that are identified in the established systems enginering data flow schemas for al aplicable product development phases, and has data change control and tracking procedures5. If
33、 a Capability Level 4 System Reliability Modeling proces is required, al data that are entered in or extracted from the System Reliability Modeling database shal be prefaced with one or more keyword data element descriptions (DED) listed in Anex C. Each keyword DED belongs to one of the folowing dat
34、a types. physical or functional characteristic physical or functional dependency aplication Failure Mode and Efects Analysis (FMEA) 5The objective here is to ensure that al failure modes and critical items are documented, the history of designed-in reliability improvements is maintained, and curent
35、data is distinguishable from out-of-date data. ANSI/AIA S-102.2.2-2009 10 criticality analysis6 maintainability analysis Anomaly Detection and Resolution (ADR) reliability, system safety, and maintainability critical Item failure compensation identification unit reference value coment atachment data
36、base administration The System Reliability Modeling database shal be structured to alow: (1) independent verification of the interdependencies for al component-level functions that are Severity Clasification 3, 4, or 5, and (2) online review of the most curent and al prior graphical reliability mode
37、ls or RBD. If a Capability Level 4 System Reliability Modeling proces is required, the contractor shal establish and maintain a seamles interface betwen the System Reliability Modeling database, Product FMECA/Hazards Analysis database, and the project R B.1.3 Timely integration and procesing of the
38、individual mathematical or simulation models of the system to estimate the probability of the overal system sucesfuly performing its intended functions for each specified mision time period or operating cycle, and under specified operating conditions; B.1. 4 Timely development and documentation of a
39、 System Reliability Predictions Report that reflects the curent state of the system design to the greatest extent practical, and identifies the hardware or functional elements of the system that are not included in the system reliability model, along with rationale for each elements exclusion from t
40、he model. B.2 The Capability Level 2 System Reliability Modeling Proces shal include al the tasks in the Capability Level 1 System Reliability Modeling Proces plus the folowing at a minimum: B.2.1 Timely colection or development, as necesary, of the folowing system design and operating information t
41、o be used for the construction of mathematical or simulation models for system reliability predictions: The initial reliability9of each system item that performs an esential function in each specified mision time period or operating cycle 9Initial system reliability includes the cumulative efects of
42、 functional testing, storage, handling, packaging, transportation, asembly, and maintenance on the inherent and operational capabilities of the system to met its reliability requirements ANSI/AIA S-102.2.2-2009 17 The efects and probability of the system being in an known undesirable state, such as,
43、 an unmitigated known sneak circuit condition, in each specified mision time period or operating cycle The historical operational data for legacy or similar systems that identifies the number, times, and severity of unanticipated failures, such as, overloked sneak circuits and latent design weaknese
44、s. B.2.2 Timely utilization of the Product FMECA to the greatest extent practical to develop the system reliability model. B.3 The Capability Level 3 System Reliability Modeling Proces shal include al the tasks in the Capability Level 2 System Reliability Modeling Proces plus the folowing at a minim
45、um: B.3.1 Timely colection or development, as necesary, of the folowing system design and operating information to be used for the construction of mathematical or simulation models for system reliability predictions: Inherent reliability characteristics of each software component that performs an es
46、ential function in each specified mision time period or operating cycle Inherent reliability characteristics of each operator or user that performs an esential function in each specified mision time period or operating cycle B.3.2 Timely development, documentation, and flow down, as apropriate, of a
47、 System Reliability Modeling Proces Plan that is based on industry-acepted concepts for performance-based practices and is an integral part of the R B.3.3 Timely development and maintenance of a System Reliability Modeling database that is compatible with the Product FMECA/Hazards Analysis database
48、and can generate a System Reliability Predictions Report; B.3.4 Timely utilization of System Reliability Modeling results/data to the greatest extent practical by project functions, such as, Design, System Safety, Logistics, Risk Management, Test, and R B.3.5 Timely colection and review of existing
49、System Reliability Modeling lesons learned that are: (1) derived from sources internal to the enterprise, and (2) relevant to the system being developed. The objective of this activity is to identify neded System Reliability Modeling proces improvements; B.3.6 Timely evaluation of al aspects of the System Reliability Modeling proces, including its implementation and data products, to identify candidate product-based and proces-based lesons learned candidates. Prioritize these candidate lesons learned and forward them to the Lesons Learned A
