Downloaded from https://www.everyspec.com r.- AMCP 7M0-l" Mg~mule No. 20 - Three components are tested: No. . was censored after 3 hr; No. 2 was oensored after 6 hr; No. 3 fall ed in I hrl i.o., r - 1. The parts undergo the tout conditions during 15% of the mishdoa and are in benign circumstances otherwise, Determine the equivalent failure rate for the mission. Procedure Example 1. 11ate the failure rate as- 1. During operating phase, the failure rate it the sunmption for all phases of same as on the test. During benign phase, it mission. is assumed to be 5% of the "operating" value. 2. Estimate the "uporating" 2. - 1/1(3 + 6 + 1)-hr failure rate. Use EQ. 2-67. = 0.2 per hr. 3.
Estimate the "benign" fail- 3. - MVP ure rate, 0.005 per hr. 4. State the fraction of time in 4. . , .15 LWh•slhu. h,, 0. 85. 5. Calculate the equivalent 5. A x hours u 0.1 x 0. 15 + 0.005 x 0. 88 0.019, misioes failure rate. Use Eq. 2-68. 6. Estimato the coefficient of 6. - 1/YT-I 0.71, variation for эoP. Use Eq. 2 -69. The estimates of failure rates for a given test condition can be updated as more test data bcome available from component level testing. Tests conducted at higher levels (such as subsystem oi- equipment tests) which are monitored for failure causes a,so can provide data for updating failure ratem.
These data must indicate the actual time that each component operates In each mission phase (subphase); see Example No. 21. 21 I *,sI',IIs,..• W2-117 "' S!