AlwaysRain Irrigation, Inc., would like to determine capacity requirements for the next four years. Currently two production lines are in place for making bronze and plastic sprinklers. Three types of sprinklers are available in both bronze and plastic: 90-degree nozzle sprinklers, 180-degree nozzle sprinklers, and 360-degree nozzle sprinklers. Management has forecast demand for the next four years as follows:
Yearly Demand
1 (in 000s) 2 (in 000s) 3 (in 000s) 4 (in 000s)
Plastic 90 32 44 55 56
Plastic 180 15 16 17 18
Plastic 360 50 55 64 67
Bronze 90 7 8 9 10
Bronze 180 3 4 5 6
Bronze 360 11 12 15 18
Both production lines can produce all the different types of nozzles. The bronze machines needed for the bronze sprinklers require two operators and can produce up to 12,000 sprinklers. The plastic injection molding machine needed for the plastic sprinklers requires four operators and can produce up to 200,000 sprinklers. Three bronze machines and only one injection molding machine are available. What are the capacity requirements for the next four years? (Assume that there is no learning.)
chapt6 exeercise 113
1. Francis Johnson's plant needs to design an efficient assembly line to make a new product. The assembly line needs to produce 15 units per hour and there is room for only four work-stations. The tasks and the order in which they must be performed are shown in the following table. Tasks cannot be split and it would be too expensive to duplicate any task
Task Task time (minutes) Immediate Predecessor
A 1 -
B 2 -
C 3 -
D 1 A, B, C
E 3 C
F 2 E
G 3 E
a. Draw the precedence diagram
b. What is the workstation cycle time?
c. Balance the line so that only four workstations are required. Use whatever method you feel is appropriate.
d. What is the efficiency of your line balance?