Implementation And Optimization Study Of RAMI Analysis In NFM Project

Due to ITER project with high complexity, long cycle and high cost, which with 20 years working period (not including period of development phase), the integrated scheme of preventive maintenance in the later period especially need to be more focused. And lower product reliability also will lead to high maintenance costs, and with the increased year by year, the normal operation of the project will also be affected. Considering this situation,we design a scheme of reliability design and analysis of ITER project, which be defined as RAMI (Reliability, Availability, Maintainability, Inspectability) analysis procedure. The main purpose of RAMI analysis is to analyze the reliability, availability, maintainability and inspectability of the system by implementing a series of processes and methods relevant to reliability engineering, and finally achieve the both quantitative and qualitative reliability requirements.The main steps of the analysis include the following steps. The first step is the breakdown of system function, which used method of IDEF(?) (Integration Definition Function Modeling-language (?)) to construct IDEF model under Microsoft Visio software. This is based on the SADT (Analysis and Design Technique Structured) method, mainly through the intuitive model from the upper to the lower, reflecting the system function among each system level, subsystem level until the component module level, and also reflecting the interface between functions; The Second step is the analysis of FMECA (Failure Modes Effects and Criticality Analysis), to define the optimization analysis procedure, mainly include determining analysis object, function breakdown, determining failure mode, defining failure effect, risk assessment for severity and occurrence, distribution of all risk by severity matrix; The third step is to simulate operation to evaluate reliability and availability by RBD(Reliability Block Diagrams) model, which can through the intuitive model from the upper to the lower, to reflecting the function model of object system. and make Simulation and calculation for each functional model according to the project operation environment (qualitative requirements) and reliability availability requirements (quantitative requirements). The last step is to optimize the technical risk to the safety threshold or completely eliminate by carry out the mitigation measures.Through the implementation of RAMI analysis process, the final RAMI assessment scheme not only meets the quantitative requirements of the project reliability, but also achieves the qualitative requirements of the reliability optimization, which meets the most requirements of the customer. So that the analysis of reliability for project can be carried out by the standardization procedure of RAMI analysis, which can make the reliability analysis work c developed more reasonable and methodical separately in design, production, testing, commissioning, operation and maintenance phase of the project, and can make a traceability scheme by defining technical risk control plan to ultimate system function to meet the customer’s reliability requirements.