A producer of inkjet printers is planning to add a new line of printers, and you have been asked to balance the process, given the following task times and precedence relationships. Assume that cycle time is to be the minimum possible.

Task Length

(minutes)

Immediate

(Predecessor)

a 0.2 –

b 0.4 a c 0.3 –

d 1.3

b, c e 0.1 –

f 0.8 e g 0.3

d, f h 1.2 g

a. Do each of the following:

(1) Draw the precedence diagram.

(2) Assign tasks to stations in order of most following tasks. Tiebreaker: greatest positional weight.

(3) Determine the percentage of idle time.

(4) Compute the rate of output in printers per day that could be expected for this line, assuming a 420-minute working day.

b. Answer these questions:

(1) What is the shortest cycle time that will permit use of only two workstations? Is this cycle time feasible? Identify the tasks you would assign to each station.

(2) Determine the percentage of idle time that would result if two stations were used.

(3) What is the daily output under this arrangement?

(4) Determine the output rate that would be associated with the maximum cycle time.

Chapter Six Process Selection and Facility Layout 293

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