1. Activity on Arrow (AoA) Network Diagrams
K, L depends on A, B
K depends on A, B A A K K a. b. B B L
K depends on A but L depends on both A, B
K depends on A, B and L depends
only on B A K A K c. d. B L B L

2. f. e. A K A K C C M B L B L K depends on A, C and L depends on B, C
K depends on A, C; L depends on B, C
and M depends on C

3. Air Traffic Control Tower
A proposed ATC tower uses a control console which has to be meet the needs of the particular airfield.
Activities Involved Duration (weeks)
Design console 3
Order console 2
Fabricate and deliver console 16
Install console 2
Test console 4
Design tower 5
Design foundations 1
Order foundations material 1
Deliver foundations material 1
Construct foundations 1
Order tower construction materials 2
Deliver tower construction materials 3
Erect tower
1. Draw the AoA network diagram (assuming that design of the foundations is dependent on the design of the tower).
2. Fill in all the information in the Table’s outline of the Early, Late, Floats and determine the Critical Path

4. AoA Network Diagram (ATC tower)
Design console
Order console
Fabricate and deliver console 2 4 3 2 16
Order
fnd.
material
Deliver
fnd.
material
Design
tower
Design
fnds.
Construct
fnd.
Erect
tower
Install
console
Test
console 8 10 12 14 18 20 22 24 5 1 3 3 3 3 3 3
Order tower
material
Deliver tower
material 16 3 3

5. Activity Duration Description ES LS EF LF TF FF Critical Path *
0-2 3
Design console *
0-8 5
Design tower 8
2-4 2
Order console
4-20 16
Fab.& deliver console 21
8-10 1
Design found. 9 6 10 4
8-16
Order tower materials 7
10-12
Order found. materials 11
12-14
Deliver found. materials 12
14-18
Construct found. 13
16-18
Deliver tower material
18-20
Erect tower 18
20-22
Install console 23
22-24
Test console 27

6. Note: When to use IDENTITY and LOGIC “dummy” activities indicated in the CPA notes on Prof. Rowlinson’s Y2 notes
Refer to:
Lockyer, Keith (1984) Critical Path Analysis and other Project Network Techniques, Pitman, London. (pg 19-22)
Main Library L81