(صورة توضيحية فقط)
For a system of components in series, where any single failure causes system failure, the overall failure rate is the sum of individual rates. The system’s MTBF is the reciprocal of this sum: [latex]MTBF_{system} = (\sum_{i=1}^{n} \lambda_i)^{-1} = (1/MTBF_1 + 1/MTBF_2 + … + 1/MTBF_n)^{-1}[/latex]. This implies the system’s MTBF is always less than the lowest individual component’s MTBF.
This principle highlights a critical aspect of system design: a chain is only as strong as its weakest link. When components are arranged in series, the overall system reliability is always lower than the reliability of the least reliable component. For example, consider a system with two components in series. Component 1 has an MTBF of 10,000 hours ([latex]\lambda_1 = 10^{-4}[/latex] failures/hour) and Component 2 has an MTBF of 20,000 hours ([latex]\lambda_2 = 0.5 \times 10^{-4}[/latex] failures/hour).
The total system failure rate is [latex]\lambda_{system} = \lambda_1 + \lambda_2 = 10^{-4} + 0.5 \times 10^{-4} = 1.5 \times 10^{-4}[/latex] failures/hour. The system’s MTBF is then [latex]MTBF_{system} = 1 / \lambda_{system} = 1 / (1.5 \times 10^{-4}) \approx 6,667[/latex] hours. This is significantly lower than the MTBF of either individual component.
This calculation is foundational to the use of Reliability Block Diagrams (RBDs), a graphical method for analyzing system reliability. In an RBD, components in series are drawn in a line, visually representing that all must function for the system to succeed. This analysis drives engineers to identify critical components and focus reliability improvement efforts, such as selecting higher-quality parts or introducing redundancy (parallel components).
متوسط الوقت بين الأعطال للمكونات المتسلسلة
(إذا كان التاريخ غير معروف أو غير ذي صلة، على سبيل المثال "ميكانيكا الموائع"، يتم توفير تقدير تقريبي لظهوره الملحوظ)
الصور والتنزيلات بالحجم الكامل متاحة فقط، ومجانية تمامًا، للأعضاء المسجلين.
> تسجيل الدخول <
