View the step-by-step solution to:

A machine has a time-to-first-failure distribution that is Weibull with = 2.10 and = 620 operating hours. Assume an average usage of the machine of...

1. A machine has a time-to-first-failure distribution that is Weibull with β = 2.10 and θ = 620

operating hours. Assume an average usage of the machine of 150 hours per year.

(a) The manufacturer of the machine offers a 10-year warranty if the customer purchases their

10-year service plan. The service plan will replace all worn parts each year, thus restoring the

machine to "as-good-as-new" condition. Compare the machine reliability at 10 years with and

without the service plan.

(b) The repair time distribution of the machine is lognormal with a shape parameter of 0.60 and a

median repair time of 8 hours. The service centre advertises that if you bring them a broken

machine, it will be repaired by the same the following workday. Find the MTTR and the

percent of repairs that are completed within an 8-hour workday.

(c) Failure of a broken machine results in minimal repair that can be described by the following

intensity function (a nonhomogeneous process): ρ(t) = 6.0 × 10-6 t1.15 with t measured in

operating hours. Assume that the customer does not accept the service plan in (a).

(i) What is the expected number of failures that will occur over 10 years?

(ii) What is probability of at least one failure during the tenth year?

(iii) What is the MTBF (instantaneous) at the end of the 10th year?

Recently Asked Questions

Why Join Course Hero?

Course Hero has all the homework and study help you need to succeed! We’ve got course-specific notes, study guides, and practice tests along with expert tutors.

-

Educational Resources
  • -

    Study Documents

    Find the best study resources around, tagged to your specific courses. Share your own to gain free Course Hero access.

    Browse Documents
  • -

    Question & Answers

    Get one-on-one homework help from our expert tutors—available online 24/7. Ask your own questions or browse existing Q&A threads. Satisfaction guaranteed!

    Ask a Question