ROOTCASTLE / LABORATIO INGENIORUM
Fiducia laboratorium
MTBF, vita Weibull et mathesis redundantiae.
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
Quid est
Si quot annorum diebus in quibus equipamentum deponatur, quantum redundantis unitatem realiter emat, an ubi partium intervallem substitutionis initium sit. MTBF, Weibull et mathematicia redundantiae cum suis aequationibus ostenditur; assumptiones mutare et sensibiltatem resultati videre.
Limites
Figures MTBF Manufacturer sunt predictiones pro data temperatura et onus; conditions campestres aliae results aliae. Mathematica redundantiae assumit unitates finiri independently; causas communes qualis power supply shared, idem bug software neque error maintenance redunt benefit real. Functiones de necessitate assessment separatum sub IEC 61508 / ISO 13849.
Referentia
IEC 61703:2016 (mathematical expressions for reliability, availability, maintainability) · IEC 61649:2008 (Weibull analysis) · P. D. T. O’Connor, A. Kleyner, Practical Reliability Engineering, 5a ed. · NIST/SEMATECH e-Handbook, Assessing Product Reliability
Modelus educationalis. Resulta non sunt sufficientia ad diagnosim machinam aut definire fines operandi saluti.