the H-bridge C2 Package failure rate Based on equation from .0056 MIL-Hnbk-217f page 5-14 [1] for SMT with 16 pins Environment factor Handbooks value for 4 πE mobile devices Quality factor Assumed from the notes 10 πQ that this is the value to use, most likely the value is too large Learning factor Number used for devices πL 1 older than 2 years in production Failure rate per 10^6 λP 6.024 hours Mean Time To Failure Approximately 19 years to MTTF 166002.656 a failure for one device CTS CB3 HCMOS/TTL Clock Oscillator [5] Model Equation: Parameter name Description Value Comments Base failure rate Based on the .027 λb [1] for devices with 20 MHz frequency Quality factor Based on devices with a 2.1 πQ non MIL-SPEC Environment factor Handbooks value for 10 πE mobile devices Failure rate per 10^6 Based on a quartz oscillator λP .567 hours calculation MTTF Mean Time To Failure Approximately 201 years to 1763668.43 a failure for one device The overall system of this project is reliable. All of the parts have a reliability within the same scale of 10^-6 failures per hour. Also, the system will not be a highly bought solution; therefore a slightly higher failure rate is acceptable. The best way to improve reliability of the design would be to buy military parts, which would reduce each by a factor of 5. This could be an acceptable increase in price because the niche for the market of this product is so small, so someone buying this would be willing to pay more. Failure Mode, Effects, and Criticality Analysis (FMECA)
the H-bridge C2 Package failure rate .0056 Based on equation from MIL-Hnbk-217f page 5-14 [1] for SMT with 16 pins πE Environment factor 4 Handbooks value for mobile devices πQ Quality factor 10 Assumed from the notes that this is the value to use, most likely the value is too large πL Learning factor 1 Number used for devices older than 2 years in production λP Failure rate per 10^6 hours 6.024 MTTF Mean Time To Failure 166002.656 Approximately 19 years to a failure for one device CTS CB3 HCMOS/TTL Clock Oscillator [5] Model Equation: Parameter name Description Value Comments λb Base failure rate .027 Based on the [1] for devices with 20 MHz frequency πQ Quality factor 2.1 Based on devices with a non MIL-SPEC πE Environment factor 10 Handbooks value for mobile devices λP Failure rate per 10^6 hours .567 Based on a quartz oscillator calculation MTTF Mean Time To Failure 1763668.43 Approximately 201 years to a failure for one device The overall system of this project is reliable. All of the parts have a reliability within the same scale of 10^-6 failures per hour. Also, the system will not be a highly bought solution; therefore a slightly higher failure rate is acceptable. The best way to improve reliability of the design would be to buy military parts, which would reduce each by a factor of 5. This could be an acceptable increase in price because the niche for the market of this product is so small, so someone buying this would be willing to pay more. Failure Mode, Effects, and Criticality Analysis (FMECA)
hw11_grp7.docx