2024 – 9 11 Stanford Rosenberg Computing wants to establish an assembly line for producing a new product the Personal

9.11 Stanford Rosenberg Computing wants to establish an  
assembly line for producing a new product, the Personal Digital  
Assistant (PDA). The tasks, task times, and immediate predecessors  
for the tasks are as follows:  
  
TASK TIME (sec) IMMEDIATE PREDECESSORS
A 12 __
B 15 A
C 8 A
D 5 B, C
E 20 D
a) What is the cycle time?
b) What is the theoretical minimum for the number of workstations
that Rosenberg can achieve in this assembly line?
c) Can the theoretical minimum actually be reached when workstations are assigned? PX

9.13 Sue Helms Appliances wants to establish an assembly  
line to manufacture its new product, the Micro Popcorn  
Popper. The goal is to produce five poppers per hour. The tasks,  
task times, and immediate predecessors for producing one Micro  
Popcorn Popper are as follows:  
  
TASK TIME (min) IMMEDIATE PREDECESSORS
A 10 __
B 12 A
C 8 A, B
D 6 B, C
E 6 C
F 6 D, E
  
a) What is the theoretical minimum for the smallest number of  
workstations that Helms can achieve in this assembly line?  
b) Graph the assembly line and assign workers to workstations.
Can you assign them with the theoretical minimum?
c) What is the efficiency of your assignment? PX

9.15 The following table details the tasks required for   
Indiana-based Frank Pianki Industries to manufacture a fully   
portable industrial vacuum cleaner. The times in the table are in   
minutes. Demand forecasts indicate a need to operate with a cycle   
time of 10 minutes.   
   
ACTIVITY ACTIVITY DESCRIPTION IMMEDIATE PREDECESSORS TIME
A  Attach wheels to tub _ 5
B Attach motor to lid _ 1.5
C Attach battery pack B 3
D Attach safely cutoff C 4
E Attach filters B 3
F Attach lid to tub A, E 2
G Assemble attachments  _ 3
H Function test D, F, G 3.5
I  Final inspection  H 2
J Packing  I 2
   
a) Draw the appropriate precedence diagram for this production line.    
b) Assign tasks to workstations and determine how much idle time is present each cycle.
c) Discuss how this balance could be improved to 100%.
d) What is the theoretical minimum number of workstations? PX