An electrical appliance is to be assembled on a production flow line. The total job is divided into 12 rational discrete elements which cannot be split further. The IE department has time estimates for these elements as tabulated below. The demand is forecasted to be 120,000 units per year at 50 weeks/year and 40 hours/week.

a. Draw the precedence diagram

b. What is the required cycle time to meet the forecasted annual demand of 120,000 units?

c. What would be the minimum number of workstations?

d. Assign tasks to workstations based on the longest task time. Show it through a demarcation in the precedence diagram.

e. What is the line efficiency thus achieved? What is the balance delay of the line by virtue of this balancing?
 

Elements A B C D E F G H I J M L Time in minutes 0.2 0.4 0.7 0.1 0.3 0.11 0.32 0.6 0.27 0.38 0.5 0.12 Predecessor element(s) A A, B B C C, D F, G, H E I, J K