QUAL8320
Assignment # 5 – Quality Techniques
(7 marks)
The inner lining of automotive doors is a plastic extruded molding, as shown here:
Table 1 is an Activity Network Data Table showing all the project activities involved in
manufacturing these extruded plastic inner linings.
Table 1
ID
Task Description
A
Polymer received and stored
B
Inspection
C
Predecessor
Normal
Duration (hrs.)
Crash
Duration (hrs.)
Normal Cost
of Activity ($)
Additional
Cost/hr. to Crash
12
12
$1500.00
A
2
2
$200.00
Material blending
B
4
4
$100.00
D
Chemical additives
C
1
1
$125.00
E
Polymer drying
D
12
11
$800.00
$100
F
Stabilizer added
D
5
4
$150.00
$50
G
Polymer fed to extruder
E, F
2
2
$80.00
H
Extrusion
G
3
3
$225.00
I
Shaped and drawn
H
1.5
1.5
$300.00
J
Solidification
I
2
2
$250.00
K
Cooling
J
6
6
$130.00
L
Pulse dimensional control
K
2
1
$85.00
$30
M
Secondary control
K
6
4
$110.00
$125
N
Decorate
L, M
2.5
2.5
$75.00
O
Final inspection
N
2
2
$180.00
P
Packaging
O
2
2
$155.00
Crashing the Project: Crashing is the method of shortening the project’s overall duration by
reducing individual activity durations. This can be achieved by adjusting
the scope or adding resources.
Note: There is an overhead cost/hr. of $20.00 (for administration etc.)
(a) Create an Activity Network Diagram
(b) What are all the possible paths and durations?
(c) What is the critical path and duration?
(d) What is the normal total cost and duration?
(e) What is the crash total cost and duration?
(f) After crashing, has the critical path changed? If so, what is the new critical path and
duration?
(g) Are there any activities that are not worth crashing? Explain.
(h) On average, how much extra does it cost/hr., if this project is crashed?
(i) What is the optimistic and pessimistic critical path durations?
Note: This is a group assignment as per assigned groups.
*************************************************************************
Ensure to reference any material taken from lecture slides, course material, textbooks and
any other sources used to support this assignment.