Formulas (dont know if we have to use them here):

Maintenance/reliability Company PeltBesk produces reltier elements. Their machines have a MTTF of 535 hours and a MTTR of 65 hours. In a month the machines operate 220 hours. Company BioTronic uses these elements in series to make a product (they had 3 different products; one had no elements in series, one had 2 elements in series and one had 3 elements in series). In a first quality control they see if the products functions correctly or not. If it doesn't function correctly they throw it away. In a second quality control, which is a visual inspection, they look at the connections between the elements. The connection is important for the lifespan: bad connection: F(t) = 1 -ent-1/4.6) good connection: R(t) = e^(-t/12) BioTronic receives complaints from their customers saying the products are not meeting the contractually agreed reliability (t = 2 years) of 85%. Upon hearing this an engineer at PeltBeck does a calculation and he does in fact get an reliability of 85%. 1. What is the availability of the machine? What can you say about the r(t) of this machine? What can you say about the 'bathtub curve'? Availability - MTBF/(MTBF-MITR) Does someone know how to calculate MTBF? is it just 3/4.67 -> 3 element in series times the lambda of the bad connection? MTBF = MTTR+MTTF r(t) = f(t)/R(t) 3. bit LA 12. Requited from in that we will use FC) - prob that a campement faits at a hefur teure t* f(t) = derivature of FCH) R(t) = reliability e rekability function RwE) + FA)=1* + FE) = FCIL fachere rate in the chance that the chance that a component that has surived "RU up to time to faily in the next instant Carly valil for Small time frames r(t) *st In Exam only depends 2nd feature type : exponention, random on one parametr r(t) = 1 failure rate fails twee per year. 1 meantime A ( -R(t) = ent -F(t) - 1-pole f(t) = del