Finance Problems Chapter 9
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)EDECESSORS
Task Time Immediate Processor
A 12 –
B 15 A
C 8 A
D 5 B,C
E 20 D
Rosenberg’s goal is to produce 180 PDAs per hour.
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
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 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?
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
ACTIVITY ACTIVITY DESCRIPTION
A Attach wheels to tub — 5
B Attach motor to lid — 1.5
C Attach battery pack B 3
D Attach safety 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
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%.