Operations Management Project: Assembly Line Balancing Analysis

This operations management project solution focuses on assembly line balancing, specifically addressing cycle time optimization and workstation design. The solution includes calculations for theoretical workstations and line efficiency, demonstrating how to assign tasks to workstations based on precedence relationships and cycle time constraints. Two scenarios are analyzed: one with an initial task time and another with a reduced task time for one of the operations. The project uses the principle of assigning the longest eligible task to each workstation without exceeding the desired cycle time. The line efficiency is calculated for both scenarios, showcasing the impact of task time reduction on overall efficiency. The project concludes with a revised workstation design, reflecting the changes in task times and their effect on balancing the assembly line. Desklib offers this and many other solved assignments for students.

Operations Management Project
Name
Institution
Date

Question 3: Done in Excel Sheet (Attached)
Question 6 Solution
Network Diagram
Solution
a. Desired Output = 6
Operating Time = 60 minutes (1 hour)
Cycle Time = OperatingTime
Desired Output =60 minutes
6 =10 minutes per unit
Task Immediate
Predecessor
No. of Following
Tasks
Task Time
(Minutes)
Positional
Weight
A None 4 7 26
B None 4 4 23
C A 2 2 13
D A,B 2 8 19
E B 2 3 14
F C,D,E 1 2 11
G None 1 2 11
H None 2 4 15
I F,G 0 9 9
Total Task Time 41
Theoretical Work Stations = TotaTask Time
Cycle Time = 41
10 =4.1 ≈5 workstations
Assigning Tasks to Workstations
Principle used:
We are going to start at the first workstation and select the longest eligible task based on the
precedence relationship or tasks with highest number of followers. This process of adding the
A 7
B 4
D 8
C 2
E 3
H 4
F 2
G 2
i 9

longest eligible task will continue as long as the desired cycle time is not exceeded, i.e. 10
minutes. When there is no additional tasks to be added within the calculated cycle time, the rest
of the tasks are assigned to the next workstation.
Based on this principle, we start assigning task A to Workstation I which has a duration of 7
minutes. The remaining or idle time will therefore be: 10-7 = 3 minutes. Therefore, C which has
duration of 3 can be assigned along with A since total task time for A and C will be 7+3 = 9
minutes (which is less than desired cycle time, 10 minutes)
Tasks B and E are assigned to Workstation II whose total time is: B+E = 4+3 = 8 (≤ 10)
Task D is assigned to workstation III, D = 8 (≤ 10)
Tasks H, F and G are assigned to workstation IV. Total task time = 4+2+2=8 (≤ 10)
Task I is assigned to workstation V, whose task time = 9 minutes.
Table 1: Assembly Line Balancing Table (Cycle Time=10 minutes)
Workstation Eligible Task Task Selected Task Time Idle/Remaining
Time
I A A 7 3
B,C,D C 2 1
II B B 4 6
D,E E 3 3
III D D 8 2
IV F F 2 8
G G 2 6
H H 4 2
V I I 9 1
The workstations can be presented as follows:

b. Line Efficiency = Total task time/{Theoretical number of stations*cycle time} =
41/{5*10} = 0.82
Efficiency = 82%
c. If e takes 1 minute
The precedence diagram will be as shown below:
Task Immediate
Predecessor
No. of Following
Tasks
Task Time
(Minutes)
Positional
Weight
A None 4 7 26
B None 4 4 23
C A 2 2 13
D A,B 2 8 19
E B 2 1 12
F C,D,E 1 2 11
G None 1 2 11
H None 2 4 15
I F,G 0 9 9
Total Task Time 39
Total task time = 39
Theoretical Work Stations = TotaTask Time
Cycle Time = 39
10 =3.9 ≈ 4 workstations
Using the precedence rule, the best possible assignment of tasks to the workstation will be as
follows:

Table 2: Assembly Line Balancing Table (Cycle Time=10 minutes)
Workstation Eligible Task Task Selected Task Time Idle/Remaining
Time
I A A 7 3
B,C,D C 2 1
II B B 4 6
D,E E 1 5
III D D 8 2
IV F F 2 8
G G 2 6
H H 4 2
V I I 9 1
The number of station have not changed because workstation 2 will have a task time of 5 (B+E)
minutes and adding D to the same station will make it have total task time of 5+8 = 13 minutes,
which exceeds the required cycle time of 10 minutes. The possible workstation design is,
therefore, similar.
The New Line Efficiency = Tota Task Time
Theoretical No. of workstations ×Cycle Time
39
4 × 10 =0.975=97.6 %