ROOTCASTLE / इंजीनियरिंग लैब
Reliability lab
MTBF, वेबुल जीवन और अतिरिक्त गणित।
LOCAL CALCULATION · EDUCATIONAL MODEL
MTBF and availability
- Mission reliability R(t)
- 64.53 %
- Expected failures in mission
- 0.438
- Availability A
- 99.96 %
- Number of nines
- 3.4
- Expected downtime per year
- 3.5 h
- λ · FIT
- 5.00e-5 /h · 50,000
Model and assumptions
Constant failure rate (exponential distribution): R(t) = e^(−t/MTBF), λ = 1/MTBF. Inherent availability A = MTBF/(MTBF+MTTR); logistics and waiting time are not included. The probability of surviving to the MTBF is always 36.8 %: MTBF is not a guaranteed life.
R(t) = e^(−t/MTBF); A = MTBF / (MTBF + MTTR); downtime = (1 − A) · 8760 h
यह किस लिए है
To look at the same numbers when discussing how long equipment will be down per year, what a redundant unit really buys, or where a part's replacement interval should start. The MTBF, Weibull and redundancy maths is shown with its equations; change the assumptions and see how sensitive the result is.
संभावित आवृत्ति घटक
Producentų MTBF skaičiai paprastai yra prognozės, atsižvelgiant į tam tikrą temperatūrą ir apkrovą; skirtingos lauko sąlygos duoda skirtingus rezultatus. Redundancijos skaičiavimai pripažįsta, kad įrenginiai neveikia nepriklausomai; bendri veiksniai, tokie kaip bendras maitinimo šaltinis, vienas ir tas pats programavimo klaidų ar vienas ir tas pats techninės priežiūros klaidų, sumažina tikrą naudą. Saugos funkcijos reikalauja atskiro įvertinimo pagal IEC 61508 / ISO 13849.
संदर्भ
IEC 61703:2016 (mathematical expressions for reliability, availability, maintainability) · IEC 61649:2008 (Weibull analysis) · P. D. T. O’Connor, A. Kleyner, Practical Reliability Engineering, 5th ed. · NIST/SEMATECH e-Handbook, Assessing Product Reliability
शैक्षिक मॉडल। एक मशीन का निदान करने या सुरक्षित ऑपरेटिंग सीमाओं को स्थापित करने के लिए परिणाम पर्याप्त नहीं हैं।