پديد آورندگان :
مؤكدي، حميد دانشگاه علم و صنعت ايران - دانشكده مهندسي صنايع , سيدحسيني، محمد دانشگاه علم و صنعت ايران - دانشكده مهندسي صنايع , شهانقي، كامران دانشگاه علم و صنعت ايران - دانشكده مهندسي صنايع
كليدواژه :
سيستم دومؤلفه‌يي , فاصله‌ي بازرسي بهينه , بازرسي فرصت‌طلبانه , خرابي پنهان , خرابي آشكار , دومرحله‌يي
چكيده فارسي :
در اين مقاله، يك سيستم دومؤلفه‌يي بررسي مي‌شود. خرابي مؤلفه‌ي اول پنهان است؛ يعني باعث توقف سيستم نمي‌شود. ولي هزينه‌هاي عملياتي را افزايش مي‌دهد. مؤلفه‌ي دوم داراي سه وضعيت است: سالم، معيوب و خراب. وضعيت خراب، آشكار و باعث توقف سيستم مي‌شود. وقوع عيب و خرابي آشكار مؤلفه‌ي دوم باعث ايجاد شوك روي مؤلفه‌ي اول مي‌شود و نرخ خرابي آن را افزايش مي‌دهد. سيستم طبق سياست بازرسي دوره‌يي براي شناسايي خرابي‌هاي پنهان و عيب‌ها، بازرسي مي‌شود. مؤلفه‌ي اول به محض توقف سيستم نيز به صورت فرصت‌طلبانه بازرسي مي‌شود. هدف، يافتن فاصله‌ي بازرسي دوره‌يي بهينه است كه هزينه‌ي كل را در يك افق زماني
محدود كمينه كند. ابتدا، مدل بازرسي به صورت رياضي مدل‌سازي مي‌شود. سپس، به دليل پيچيدگي محاسبات عددي، يك الگوريتم شبيه‌سازي براي محاسبه‌ي هزينه‌ي كل ارائه مي‌شود. براي تشريح روش پيشنهادي، يك مثال عددي براي سيستمِ تامينِ توانِ مصرفي در پست توزيع برق ارائه شده است.
چكيده لاتين :
In this paper, the optimal periodic inspection interval over a finite time horizon for a two-component system with two types of failures is determined. The failure type of the first component is hidden. The hidden failure is not self-announcing, i.e., it does not stop the system from working. Thus, it is detected only by inspection; however, any delay in the detection of hidden failures causes an increment in operating costs. The failure type of the second component is of two stages. In other words, the second component has three possible states: healthy, defective, and failed. The defective state is identified just by inspection; however, the failed state is self-announcing, i.e., it reveals itself by stopping the system from working. Each defect and revealed failure of the second component causes a shock to the first component and increases its failure rate. Both components of the system are periodically inspected simultaneously to identify defects and hidden failures. Whenever the system stops working due to the revealed failures of the second component, the first component is also inspected opportunistically to detect the hidden failures. The first component is either minimally repaired or replaced upon
inspection if the hidden failure is detected. The second component is also
either minimally repaired or replaced upon inspection if found defective or at revealed failure. The total cost of the system includes the periodic and opportunistic inspection costs, downtime penalty costs due to hidden failures, and the minimal repair and replacement costs due to hidden failures, defects, and revealed failures. The goal is to find the optimal periodic inspection interval minimizing the expected total cost over a finite time horizon. In the introduced approach, the inspection model is first developed mathematically. Then, due to the complexity of numerical computing, a simulation algorithm is designed to estimate the expected total cost of the system. Finally, the suggested approach is explained by a numerical example with sensitivity analysis for an electrical distribution system.
