39045, d1 =3, d2=9, d3= 10, d4= 4, d5= 5. A time study of a manufacturing process producing spare parts was conducted for 3 hours and 40 minutes. The observer recorded time continuously-recording the start time of each job element. The activity consists of 6 job elements. All the job elements are implemented by a human worker except inspecting, which is an automatic process that requires no human interference. After each forth cycle the worker packs 4 parts together. The data of observations that include Performance Rating (PR) is provided in the table below. Observations (min) 4 5 1 2 3 0 25.2 51.6 72.1 102.5 1.1 26.5 52.8 73.7 104 34.4 54.6 80.5 113.4 140.5 47.6 67.7 93.4 49.5 70 6.9 (D) Drilling 21 95.6 (E) Inspecting 23.1 (F) Packaging 97.8 Job Elements (A) Cutting (B) Welding (C) Polishing 6 7 8 190.3 131 157.1 132 158.3 191.7 165.8 198.2 126.9 152.9 178.9 211.2 128.9 155 188.1 213 PR 110% 105% 110% 80% 215.1 90% Please answer the following questions. SHOW ALL CALCULATIONS and explain any assumptions you make. 1) Calculate the total normal time (20 points) 2) Suppose that the allowances for personal needs is 5%, fatigue is 6%, and unavoidable delay is 3%. Compute the standard time for producing 1 part. (20 points) 3) Assuming that all the activities (except Inspecting) are performed by the same worker (30 points) a. Calculate the workers efficiency during this observation? b. Is his efficiency good or bad and what is the reason? 4) What are the differences between performance rating and PFD allowance? (10 points) 5) Why is the standard time needed? Why is it useful? State two reasons. (10 points) 6) Calculate how many units will be produced in "(d4+d5)*10" hours. (10 points)