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Chapter 10 Layout 11. Assembly-line balancing. Longest work element rule to produce 40 units per hour. 1 1 hour 3600 sec sec 90 a. c r 40 units 40 units unit t 415 4.611 or 5 b. TM c 90 c. Sl = {A, C, E}, S2 = {B}, S3 = {G, D}, S4 = {H, F, I}, S5 = {J, K} FI HK Station S1 S2 S3 S4 S5 Candidate(s) A C E B D, F, G D, F, I F, H, I F, I I J K Work Element Time (sec) 40 30 20 80 60 25 45 15 10 75 15 Choice A C E B G D H F I J K Cumulative Time (sec) 40 70 90 80 60 85 45 60 70 75 90 t 415 100% 92.2% nc 590 Balance delay % 100% Efficiency d. Efficiency (%) 100% 92.2% 7.8% 12. Johnson Cogs D 40 B E H 30 6 20 A G 40 15 J C 30 50 F I 25 18 211 Idle Time ( c 90 sec) 50 20 0 10 30 5 45 30 20 15 0 212 PART FOUR Capacity, Location, and Layout a. Before calculating the theoretical minimum number of stations, we find the cycle time as: t 3600 sec hr 274 c 60 sec unit . Then we find TM 4.56 or 5 60 sec unit c 60 b. Task assignments using longest work-element time rule: F IJ G HK Station S1 S2 S3 S4 S5 S6 Candidates A B, C B, F, G E, F, G D, E, G E, G E, I E H J Assignment A C B F D G I E H J Cumulative Time 40 50 30 55 40 55 18 24 44 30 Idle Time ( c 60 ) 20 10 30 5 20 5 42 36 16 30 Six workstations are required. c. Largest number of followers. The number of followers for each work element are: Work Element A B C D E Number of Followers 9 4 4 2 2 Work Element F G H I J Number of Followers 2 2 1 1 0 Task assignments using largest number of followers rule: Station S1 S2 S3 S4 S5 S6 Candidates A B, C (tie) B, F, G E, F, G (tie) D, E, G (tie) E, G E, I H, I (tie) I J Assignment A C B F D G E H I J Cumulative Time 40 50 30 55 40 55 6 26 44 30 Idle Time ( c 60 ) 20 10 30 5 20 5 54 34 16 30 d. Efficiency with 5 workstations: t 100% 274 100% 9133% . Efficiency c 560 FI HK 13. Baxter Bicycle Company a. We must first determine the cycle time, expressed in seconds because the work element times are also in seconds. Layout a CHAPTER TEN f r 576 units day 8 hours shift @3 shifts day 24 units per hour c 1 24 3600 150 sec unit a f The sum of the work element times (t) is 515 seconds. TM F t I 515 343 Hc K 150 . or 4 C J 30 B D F H 50 25 55 50 A E G 75 45 70 90 I 25 b. Solution using longest work-element time rule: S3 = {H,E,C,I} Station S1 S2 S3 S4 Candidates A B D C, E, F, G C, E, F C, E, H C, E C, I I J Choice A B D G F H E C I J Cumulative Time 75 125 150 70 125 50 95 125 150 90 The third workstation would be assigned elements H, E, C, and I. Idle Time ( c 150 ) 75 25 0 80 25 100 55 25 0 60 213