Guided missiles are a one-shot system that finishes their purpose after being used once, and due to the long-term storage until launch, the storage reliability is calculated during development, and performance is maintained through periodic inspections until the life cycle arrives. However, the reliability standards applied in the development of guided missiles were established by analyzing data accumulated by the United States during long-term operation in the country, and since they are different from our environment, the 00 guided missiles that have been deployed in the armed forces for more than 10 years under the premise that there is a difference from actual reliability. As a result of verifying the appropriateness of the current inspection cycle by analyzing the actual reliability of the missile, the necessity of changing the inspection period was derived because it was higher than the predicted reliability. It is proposed to build and utilize a lifespan management system that can systematically collect all data such as shooting and maintenance results by classification, and to establish a reliable reliability standard based on the accumulated data.
A one-shot system (device) refers to a system that is stored for a long period of time and is then disposed of after a single mission because it is accompanied by a chemical reaction or physical destruction when it operates, such as shells, munitions in a defense weapon system and automobile airbags. Because these systems are primarily related with safety and life, it is required to maintain a high level of storage reliability. Storage reliability is the probability that the system will operate at a particular point in time after storage. Since the stored one-shot system can be confirmed only through inspection, periodic inspection and maintenance should be performed to maintain a high level of storage reliability. Since the one-shot system is characterized by a large loss in the event of a failure, it is necessary to determine an appropriate inspection period to maintain the storage reliability above the reliability goal. In this study, we propose an optimal inspection policy that minimizes the total cost while exceeding the reliability goal that the storage reliability is set in advance for the one-shot system in which periodic inspections are performed. We assume that the failure time is the Weibull distribution. And the cost model is presented considering the existing storage reliability model by Martinez and Kim et al. The cost components to be included in the cost model are the cost of inspection c1, the cost of loss per unit time between failure and detection c2, the cost of minimum repair of the detected breakdown of units c3, and the overhaul cost c4 of ≤ . And in this paper, we will determine the optimal inspection policy to find the inspection period and number of tests that minimize the expected cost per unit time from the finite lifetime to the overhaul. Compare them through numerical examples.
This paper is to propose various quality and reliability sampling inspection methods to perform the competitive global outsourcing strategy while purchasing and subcontracting. The study also represents implementation strategy which can be efficiently and effectively used in the enterprise. Quality sampling inspection schemes extend reliability inspection techniques with a little change.
교량의 안전은 점검에 의해 보장된다. 그리고 교량의 유지관리는 점검결과를 토대로 시작된다. 따라서 점검결과는 ‘교량의 안전’과 ‘효율적인 유지관리’를 위한 가장 중요한 정보이다. 따라서 본 논문에서는 교량의 점검신뢰도를 평가하고 이를 제고 할 수 있는 방안을 제시하 고자 한다. 이를 위해 본 논문에서는 교량의 점검신뢰도를 평가 할 수 있는 세 가지 점검신뢰도를 제시하였다: 명목점검신뢰도, 실질점검신뢰 도, DS명목점검신뢰도. 교량의 점검신뢰도 분석 방법은 정밀안전진단결과를 참값으로 간주하고 당해년도 정밀(정기)점검과 차년도 정밀안전 진단결과를 비교하였다. 인적오류를 고려한 DS명목신뢰도를 기준으로 현재 고속도로교량의 점검신뢰도 85%로 양호한 편으로 평가 된다. 이 는 현재 고속도로 교량의 평균공용연수가 13년으로 대부분의 교량이 ‘A’와 ‘B’등급에 집중적으로 분포되어 상태변화가 크지 않기 때문인 것 으로 판단된다. 점검신뢰도를 제고하기 위해서는 점검자의 역량을 강화하고 전문점검인력 육성이 필요하며 점검결과에 대해 QC(Quality Control, 품질관리)를 실시하여 점검결과의 신뢰도 향상이 필요하다.