Question 3 (20 marks) This question tests your understanding of Block 2 Part 3. You must show your working to gain full marks; about 50% of the marks are awarded for

a clear explanation of your working. • a.Explain, in your own words, the difference between reliability and availability. In each case give one way in which the concepts are expressed numerically. You should write no more than 100 words for part (a). (6 marks) b.50 components within their useful life period are tested for 100 hours and there are 27 failures. Estimate the 1,000 hour reliability of a component to 3 decimal places. (2 marks) • c.Calculate to 3 decimal places the availability of a device which fails, on average, 8 times a year, and takes an average of 10 hours to repair. (2 marks) • d.Figure 1 shows a reliability diagram for a system element of components having reliabilities of R₁ = 0.850, R₂ = 0.700 and R, = 0.950. Evaluate the overall reliability of the system, to 3 decimal places. (5 marks)/n• e.Explain three reasons why a system using independently designed software components can still fail. You should write no more than 100 words for part (e). (5 marks)