1、 Standard ANSI/AIAA S-102.2.2-2009 Performance-Based System Reliability Modeling Requirements AIAA standards are copyrighted by the American Institute of Aeronautics and Astronautics (AIAA), 1801 Alexander Bell Drive, Reston, VA 20191-4344 USA. All rights reserved. AIAA grants you a license as follo
2、ws: The right to download an electronic file of this AIAA standard for storage on one computer for purposes of viewing, and/or printing one copy of the AIAA standard for individual use. Neither the electronic file nor the hard copy print may be reproduced in any way. In addition, the electronic file
3、 may not be 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/AIAA S-102.2.2-2009 American National Standard Performance-Based System Reliability Modeling Requirements Sponso
4、red by American Institute of Aeronautics and Astronautics Approved 17 November 2008 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 numerica
5、l apportionments and reliability predictions based on the reliability characteristics and functional interdependencies for all configured items required to perform the mission. The requirements for contractors, the planning and reporting needs, along with the analytical tools are established. The li
6、nkage of this Standard to the other standards in the new family of performance-based Reliability and Maintainability (R plan the activities to achieve a level of R appraise the performance an R and identify the activities necessary to improve the performance of an R b) The description of system oper
7、ating modes and environments versus the mission 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 rel
8、iability predictions by functional components, mission-critical system functions, and applicable levels of mission success; 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 f
9、rom the model. 5 Detailed Requirements The following detailed requirements pertain to the performance-based System Reliability Modeling process defined in Annex B. ANSI/AIAA S-102.2.2-2009 8 5.1 System Design Data Collection Prior to beginning the evaluation of system failure modes, the contractor s
10、hall collect sufficient system design information to define all applicable functional and physical characteristics of the system, and the reliability attributes that fall within the analytical ground rules to be specified by the contractor (see reference 9). The system design information shall inclu
11、de all system levels, mission phases, and environments, and all normal, degraded, and contingency system modes that are applicable to each mission phase. If a Capability Level 3 or higher System Reliability Modeling process is required, this information shall be entered in the System Reliability Mod
12、eling database to allow cross-referencing functional components against official design drawings. At a minimum, the contractors analytical ground rules shall include the identification of reliability attributes for all functional and physical components that apply to the capability level of the Syst
13、em Reliability Modeling process under contract. Sufficient engineering information shall be collected to determine the maturity and confidence level of the reliability value(s) used for each functional or physical component. 5.2 System Reliability Modeling Process A reliability model shall be develo
14、ped and maintained for the system or the system of systems (SoS) if required. At a minimum, the model shall be developed to the functional component level, shall define the physical components associated with each functional component, shall define the probability of failure/success or hazard rate f
15、or each physical component, and shall provide the probability of occurrence for each unacceptable failure severity classification as defined in Table 1. If a Capability Level 2 System Reliability Modeling process is required, the model also shall provide the probability of occurrence for unanticipat
16、ed failures3for each unacceptable failure severity classification as defined in Table 1. Reliability modeling techniques shall be used that provide separate outputs for: (1) the predicted reliability of each mission critical function, and (2) predicted reliability of the system, i.e., collective rel
17、iability of the subsystems, assemblies, components, and parts. The reliability models shall be traceable to and cross-referenced to the latest approved system design schematics, drawings, and specifications. The redundancy switching devices, i.e., relays and circuits shall be clearly identified in t
18、he reliability model where applicable. The nomenclature used to identify items in reliability model shall be consistent with that used in the latest approved system design schematics, drawings, and specifications. The system reliability model shall be updated, as needed, with engineering information
19、 resulting from FMECA, tests, approved design changes, environmental studies, operations planning, and field experience. If a Capability Level 3 System Reliability Modeling process is required, the reliability modeling data products shall be compatible with the Product FMECA/Hazards Analysis databas
20、e, and the functional component reliability models shall include software and software to hardware interfaces, as necessary, to predict system reliability. 5.2.1 System Reliability Predictions The contractor shall construct a system reliability model to depict the intended utilization of the element
21、s of the system to achieve mission success. The system reliability model shall consist of a graphical system reliability model or RBD that shows all of the series-parallel functional paths that are required for successful system operation. Each reliability block in the RBD shall have a description t
22、hat includes the item identification that is traceable to design schematics or drawings, the applicable mission time and environment, the operating modes of the item across the mission timeline, the assumptions used to develop the reliability block, and the references for locating the simulation or
23、mathematical expressions used to obtain reliability values. For this standard, a single reliability block shall be used to represent a simulation instruction set, an event tree diagram, a fault tree diagram, a Markov diagram4, or a probability truth table, all of which have varied degrees of complex
24、ity, ranging from representing a single component to hundreds of components. 3For this standard, unanticipated system failures are operational anomalies that are not documented in reliability analyses or test anomaly reports. 4Markov diagram is the common name given to graphical representations of s
25、tate transition models. ANSI/AIAA S-102.2.2-2009 9 Table 1 AIAA S-102 Failure Severity Classification Failure Severity Classification Failure Effect Description CATASTROPHIC failure would cause loss of life or total disability to personnel, or failure would cause identifiably catastrophic damage to
26、system and repairs that are beyond the capability of the user or contractor to resolve the effects CRITICAL failure would cause severe disabling injury or severe occupational illness to personnel, or failure would cause identifiably critical damage to the system and extensive repairs to resolve the
27、effects MARGINAL failure would cause minor injury or minor occupational illness to personnel, and those injuries or illness may require hospitalization but they are not disabling, or failure would cause identifiably marginal damage to the system and acceptable level of repairs and downtime to resolv
28、e effects MINOR failure would cause minor injury or minor occupational illness to personnel, but those injuries or illness would not require hospitalization, or failure would cause identifiably minor damage to the system and minor repairs and short downtime to resolve effects NEGLIGIBLE failure woul
29、d cause less than minor injury and no occupational illness, or failure would cause negligible damage to the system and insignificant or no downtime to resolve effects, or failure is not credible 5.2.2 Storage/Dormant Reliability Predictions If required, the contractor shall construct a system reliab
30、ility model to depict the intended periods of system storage or dormancy, which are non-operating time in the storage environment or mission environment, respectively. The system reliability model shall consist of a graphical system reliability model or RBD that shows all of the functional paths in
31、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 portion of the system is operating while the remainder of the system is dormant, the system reliability model shall consists of an operati
32、ng portion and a separate dormant portion. 5.3 System Reliability Modeling Database If a Capability Level 3 System Reliability Modeling process is required, the contractor shall establish a System Reliability Modeling database that contains the System Reliability Modeling data products that are iden
33、tified in the established systems engineering data flow schemas for all applicable product development phases, and has data change control and tracking procedures5. If a Capability Level 4 System Reliability Modeling process is required, all data that are entered in or extracted from the System Reli
34、ability Modeling database shall be prefaced with one or more keyword data element descriptions (DED) listed in Annex C. Each keyword DED belongs to one of the following data types. physical or functional characteristic physical or functional dependency application Failure Mode and Effects Analysis (
35、FMEA) 5The objective here is to ensure that all failure modes and critical items are documented, the history of designed-in reliability improvements is maintained, and current data is distinguishable from out-of-date data. ANSI/AIAA S-102.2.2-2009 10 criticality analysis6 maintainability analysis An
36、omaly Detection and Resolution (ADR) reliability, system safety, and maintainability critical Item failure compensation identification unit reference value comment attachment database administration The System Reliability Modeling database shall be structured to allow: (1) independent verification o
37、f the interdependencies for all component-level functions that are Severity Classification 3, 4, or 5, and (2) online review of the most current and all prior graphical reliability models or RBD. If a Capability Level 4 System Reliability Modeling process is required, the contractor shall establish
38、and maintain a seamless interface between the System Reliability Modeling database, Product FMECA/Hazards Analysis database, and the project R B.1.3 Timely integration and processing of the individual mathematical or simulation models of the system to estimate the probability of the overall system s
39、uccessfully performing its intended functions for each specified mission time period or operating cycle, and under specified operating conditions; B.1. 4 Timely development and documentation of a System Reliability Predictions Report that reflects the current state of the system design to the greate
40、st 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 the model. B.2 The Capability Level 2 System Reliability Modeling Process shall include all the tasks in
41、the Capability Level 1 System Reliability Modeling Process plus the following at a minimum: B.2.1 Timely collection or development, as necessary, of the following system design and operating information to be used for the construction of mathematical or simulation models for system reliability predi
42、ctions: The initial reliability9of each system item that performs an essential function in each specified mission time period or operating cycle 9Initial system reliability includes the cumulative effects of functional testing, storage, handling, packaging, transportation, assembly, and maintenance
43、on the inherent and operational capabilities of the system to meet its reliability requirements ANSI/AIAA S-102.2.2-2009 17 The effects and probability of the system being in an known undesirable state, such as, an unmitigated known sneak circuit condition, in each specified mission time period or o
44、perating cycle The historical operational data for legacy or similar systems that identifies the number, times, and severity of unanticipated failures, such as, overlooked sneak circuits and latent design weaknesses. B.2.2 Timely utilization of the Product FMECA to the greatest extent practical to d
45、evelop the system reliability model. B.3 The Capability Level 3 System Reliability Modeling Process shall include all the tasks in the Capability Level 2 System Reliability Modeling Process plus the following at a minimum: B.3.1 Timely collection or development, as necessary, of the following system
46、 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 essential function in each specified mission time period or operating cycle Inhe
47、rent reliability characteristics of each operator or user that performs an essential function in each specified mission time period or operating cycle B.3.2 Timely development, documentation, and flow down, as appropriate, of a System Reliability Modeling Process Plan that is based on industry-accep
48、ted 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 and can generate a System Reliability Predictions Report; B.3.4 Timely
49、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 collection and review of existing System Reliability Modeling lessons 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 needed System Reliability Modeling process improvements; B.3.6 Timely evaluation of all aspects of the System Re
