Thread Content
Management of fault countermeasures I. Fault analysis 1. Purpose of analysis: At the stage of understanding the current condition of the equipment, a hierarchical analysis is carried out across different parts of the equipment, in order to identify the true causes of the specified (identified) defective conditions. 2. Basic approach when analyzing contributing factors: ① Use the symptoms identified from the current situation as characteristics for factor analysis; verify and identify the true causes among the factors that have been identified through investigation. ②Make use of daily operational data as much as possible; if no such data is available, use the latest data. Characteristics correspond to factors at this time. When data cannot be found, new data should be recorded. At this point, in order to find data that correspond to the characteristics and factors, it is important to ③ clarify the method of data collection. When daily data cannot be used for analysis (when the causal relationship between characteristics and factors is unclear), experiments or trial analyses should be conducted to examine the results of such analysis. At this point, after identifying the cause of the technical problem through analysis, it is even more necessary to investigate what lies behind the issue and whether there are problems with the management structure. 3. Points of entry for analysis: ① Start with the causes of the equipment failure (the desired state of the equipment); ② Identify the factors that lead to prolonged repair times. 4. Analysis methods: ① Cause-and-effect diagram: Organize the relationship between the characteristics of the problem (the outcome) and the factors that influence it (potential causes); ② 5Why analysis: Identify the factors that may be causing this phenomenon, and by comparing them with the facts, determine the reasons behind it. It needs to be repeated at least 5 times. ③PM Analysis: Aimed at addressing chronic problems with complex underlying causes. Analyze the phenomenon from a physical perspective, identify all factors, and restore its characteristics. ③OR-f analysis: Categorizes the various characteristics of adverse events; for each category, facts are taken as principles, and factors are identified based on those facts. Investigate and verify to identify the true cause until recurrence can be prevented. ④FTA: It is a method of analysis using logical diagrams. Break down the factors causing system failures and disasters into details in a hierarchical, tree-like structure. ⑤Association diagram method: It is a type of diagram that uses arrows to connect the relationships between a problem and the factors that affect it, in accordance with certain logical principles. It is suitable for analyzing broad issues and problems with complex interrelated factors. ⑥ System diagram method: This is a tree-like diagram that breaks down the means to achieve a certain goal in detail; it is useful when one wishes to find specific solutions to a particular problem using this approach. 5. Countermeasures: To achieve the \"goal setting,\" it is necessary to eliminate the gap between the (fault) target value and the actual (fault) performance. Therefore, it is not only necessary to take measures against the \"worst 1 failure,\" but it is also essential to accumulate failure countermeasures for failures of a comparable severity. ①Formulate countermeasure plans. These plans should be based on a fault analysis of the goals established through relevant performance indicators and the existing gaps ； Based on the issues identified with the removed equipment, considering their impact and priority, countermeasures are formulated. ②The steps for formulating countermeasures include determining the number of countermeasure items to be implemented (setting the target value to be achieved), estimating the predicted effect of each countermeasure in reducing failures, deciding on the specific countermeasure projects to be carried out, and identifying the responsible party (department), deadline, and budget for covering the associated costs. ③Decide the accumulation amount of countermeasure items. The accumulated amount of countermeasures must meet a target value in order to handle new faults as well as those for which countermeasures do not achieve 100% effectiveness. The unit for the cumulative amount of countermeasure items is failure intensity rate (%). ・To determine the amount of countermeasure items required, it is necessary to understand the current situation in order to find the difference between the target value and the actual value of the failure rate for the production line targeted by the countermeasures. ・Estimate the generation rate of the effect time of countermeasures from the difference between the average actual value and the target value of the failure intensity rate, as an accumulation amount for countermeasure items. ・Definition of the accumulated amount of countermeasures: The prerequisite accumulation rate is 130%, which is a reasonable coefficient set based on the actual conditions and patterns of on-site failures, enabling the achievement of failure targets.