HW chapter 6 OSCM

HW chapter 6 OSCM

﻿1. A manager wants to assign tasks to workstations as efficiently as possible, and achieve and hourly output of 30 units. All the tasks and their task times are shown in the diagram (times are in minutes).
a. What is the system cycle time?
b. What is the theoretical minimum number of workstations needed?
c. What is the efficiency?
d. Which of the following can be a correct result of grouping?
a. abcdegfh
b. abcdegfh
c. ab cdefgh
d. a bcedgfh

2. An assembly line with 20 tasks is to be balanced. The line will operate for 8 hours (or 480 minutes) per day. The longest task is 2.4 minutes, and the total time for all tasks is 15 minutes.
a. What is the maximum cycle time?
b. What is the daily output rate when the system cycle time is the minimum cycle time?
c. What is the minimum number of workstations needed when the system cycle time is the minimum cycle time?
d. What is the efficiency of this system after line balancing when the system cycle time is the minimum cycle time?
e. What cycle time will result in an output rate of 150 units per day?

3. As part of a major plant renovation project, the industrial engineering department has been asked to balance a revised assembly operation to achieve an output of 300 units per eight-hour day. Task times and precedence relationships are as follows:

Duration
(minutes)
Immediate
Predecessor
a
0.3
---
b
0.4
a
c
0.5
b
d
0.6
---
e
1.2
d
f
1.3
c
g
1.0
E,f

a. Determine the minimum cycle time
b. Determine the maximum cycle time
c. Determine the calculated cycle time (based on the target output rate)
d. Determine the theoretical minimum number of stations needed (based on c.)
e. Compute the percentage of idle time.

f. Draw the precedence diagram (no need to submit the answer)
g. Come up with a possible result of grouping (no need to submit the answer).