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Model Based Safety Analysis. Agenda. Safety activities within Engineering Process SIMFIA for model making and processing as integrated in the whole process Modelling approach for MBSA MBSA with SIMFIA for Airworthiness SIMFIA references. Concept and. In . Feasibility studies.
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Model Based Safety Analysis
Agenda • Safety activities within Engineering Process • SIMFIA for model making and processing as integrated in the whole process • Modelling approach for MBSA • MBSA with SIMFIA for Airworthiness • SIMFIA references
Concept and In Feasibility studies Concept and Development In Feasibility studies Development Definition Service Definition DELIVERY Service In service Follow up Change Ctrl PROCESS CONTROL , TECHNICAL STUDIES, TRAINING, DISSEMINATION CONFIGURATION MANAGEMENT PROCESS DEFINITION Item Verification Aircraft Requirements Identification System Requirements Identification Item Requirements Identification Item Design Aircraft Verification System Verification Aircraft Verification Aircraft FHA Aircraft Synthesis System Integration System Allocation PASA Aircraft CCA Aircraft CCA Item Verification Validation of requirements at the next highest level System FHA System SSA Item Integration Item Allocation System PSSA System CCA System CCA System Verification Validation of requirements at the next highest level Bottom Up Safety Requirements verification Item FMEA Item FMEA Top down RAM and safety Development Requirements & validation Item FTA Item FTA Item CMA Item CMA Validation of requirements at the next highest level Item Software Design SIMFIA Item Hardware Design Technological Design Safety Activities during development cycle
Interoperability of SIMFIA workbench designedto produce and process the models System Design Functional Hazard Analysis Additional Analysis Troubleshooting / Testability Operaters / Users Support RAMS Analysis Safety Analysis FAULT TREE Qualitative Quantitative Assessment Safety Demonstration Specification Information Data Sheet Demonstration Report Design Information SIMFIA Design process MODELS SAFETY FMECA SIMFIA Development process SIMUL RELDIAG RAMS tasks Doc / Report
Top Down Model Structure DESIGN INFORMATION REPOSITORY SYSTEM SUB SYSTEM -n Datasheets for Reports EQUIPMENT -n RAMS INFORMATION DATA BASES … -n … -n Functional/ Hazard analysis Bottom Up RAMS analysis • Model Processing • consistensy check • completeness check • scenario simulations System Engineering Tool / Workbench Framework Data / Information / Model Patterns Safety analysis Simulation/ Diagnosis
SAFETY Fault tree RELDIAG (Reliability Diagram) COST Life cycle cost Structure of SIMFIA SIMUL SOFIA Functional and Function / Hazard Simulation SOFIA Dysfunctional analysis SIMFIA SIMFIA SIMFIA SIMFIA R.A.M.S Software R.A.M.S Software R.A.M.S Software R.A.M.S Software Logistic Data Base F.M.E.C.A Fault Modes, Effect and Criticality Analysis Spreadsheets OPTIM OPTIM - - STOCK STOCK (ASCII, ...) SIMLOG Initial spares allocation Initial spares allocation SIMLOG Logistic Support Analysis Software Logistic Support Analysis COST COST Life cycle cost Life cycle cost Level Of Repair Analysis LORA Level Of Repair Analysis
Modelling Methodology for MBSA • Top Down approach: from need to solution…. • First step: specification production • Second step:solution functional specification • Third step: physical specification. • Last step: manufacturing
SOW Step 1 Specification System Step 2 FunctionalDesign F2 F1 Step 3 PhysicalDefinition Soft Step 4 Manufacturing Hard Modeling Method in MBSA approach
Reminder about the Safety process • The steps along the Safety process are following: • Functional Hazards Assessment (FHA) : A Functional Hazard Assessment is defined as a systematic, comprehensive examination of functions to identify and classify failure conditions of those functions according to their severity • Preliminary System Safety Assessment (PSSA): A PSSA is used to complete the failure conditions list and the corresponding safety requirements. • System Safety Assessment (SSA): A System Safety Assessment is a systematic, comprehensive evaluation of the implemented system to show that relevant safety requirements are met. • The SSA is a verification that the implemented design meets both the qualitative and quantitative safety requirements as defined in the FHA and PSSA • Therefore it needs, both qualitative and quantitative verification means such as FTA, FMEA, FMES etc…
FHA with SIMFIA • FHA PROCESS: • Identification of all the functions associated with the level under study (internal functions and exchanged functions) • Identification and description of failure conditions associated with these functions, considering single and multiple failures in normal and degraded environments • Determination of the effects of the failure condition • Classification of failure condition effects on the aircraft (Catastrophic, Severe-Major/Hazardous, Major, Minor and No Safety Effect) • Assignment of requirements to the failure conditions to be considered at the lower level • Identification of the supporting material required to justify the failure condition effect classification • Identification of the method used to verify compliance with the failure condition requirements
FHA with SIMFIA • The FHA is an oriented analysis of the system. SIMFIA can be used as a support for such analysis using a specificication « high level » model
FHA with SIMFIA • High level / functional view of the system.
FHA with SIMFIA • User data to input the columns content for each Failure condition • This allows to document all functional knowledge of the system in a Simfia Model for further processing of this knowledge • Fully FHA – compliant output
PSSA / SSA with SIMFIA • PSSA / SSA Process • Preliminary / Final technical « breakdown » of the functions • Model all equipments and link them to the functions
PSSA / SSA with SIMFIA • The functionnal model can be used to generate the table containing all quantitative objectives • There again thanks to user data available in SIMFIA
PSSA / SSA with SIMFIA • The expected probability can then be evaluated using the full model with technical equipments for each FC using FTA analysis (one FTA per phase)
SIMFIA V2 connectors to capture external information • Functional Analysis languages: SADT, SART, APTE… • Hardware Modelling languages : EXPRESS , SIMLULLINK, MACAR… • Performance analysis languages: PETRI, Queue Network… • Formal languages: STATE MATE…