Analysing the AoN network

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Analysing the AoN network

• Project Management
• (seminar)

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Data on the activity node
Activity label description
Total Float
EST
EFT
LST
LFT
Duration
3
Total Project Time

• The shortest time in which the project can be
  completed. Determined by the critical path.
• Calculation forward pass
• Forward pass The earliest start times (EST) of
  all activities are calculated.
• Trom these the earliest finishing times (EFT)
  are also calculated

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Critical path

• sequence of activities that has no float time,
  and that determines the duration of the project.
  It is the longest path. Activities on the
  critical path are the critical activities.
• The critical path can be identified by a backward
  pass, calculating the Latest Finishing Times
  (LFT), and from these the Latest Starting Times
  (LST).

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Floats in AoN

• Total float the time by which an activity can be
  delayed or extended without affecting the TPT.It
  can be used to delay the start of an activity or
  to increase its duration. TF LST - EST
• Free float the time by which an activity can be
  delayed or extended without affecting the start
  of any succeding activity. FF ESTj1 - EFTj

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Example organising a conference

• Objectives to organise a 3 days long open
  scientific conference with 100-200 participants,
  30-50 lectures, buffet reception, a conference
  book of the best studies and TV and radio
  interviews with some of the most known lecturers.
• Create the WBS chart and create the task list
  with estimated durations and precedence relations
  (in a table form)
• Plot both the AoA and AoN diagram
• Calculate the TPT, identify the critical path the
  total and the free float times.

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Example WBS
Project
Book
Marketing
Event management
Organising interviews
Editing
Publishing
Arranging event
Infra-structure
Organising participants
Invitation and marketing
Collecting articles
Peer reviewing
Staff
Facilities
Materials
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Task list with precedence relations
Activity label Task description Duration Immediate predecessors
a Invitation
b Organising participants
c Facilities
d Staffing
e Materials
h Collecting articles
j Peer reviewing
k Publishing
l Organising interviews
m Arranging event
Activity label Task description Duration(weeks) Immediate predecessors
a Invitation 2
b Organising participants 4
c Facilities 3
d Staffing 4
e Materials 3
h Collecting articles 6
j Peer reviewing 3
k Publishing 5
l Organising interviews 1
m Arranging event 1
Activity label Task description Duration(weeks) Immediate predecessors
a Invitation 2
b Organising participants 4 a
c Facilities 3 b
d Staffing 4 b
e Materials 3 b
f Collecting articles 6 b
g Peer reviewing 3 f
h Organising interviews 1 c, d, e
i Publishing 5 g
j Arranging event 1 h, i
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AoA
3
c
4 d
2a
4b
1h
3e
1j
6
5
TPT 21
f
i
3g
CP a-b-f-g-i-j
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AoN
1
0
0
0
0
9
1
0
0
0
TPT 21 CP a-b-f-g-i-j
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Activity times for the previous diagram(continue
individually)
Activity Duration EST LST EFT LFT Total float Free float
a 2 0 2 0 2 0 0
b 4 2 6 2 6 0 0
C 3 6 9 16 19 10 1
d
e
f
g
h
i
j
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Example 2 (for individual practice)

• a) Draw the AoA and AoN diagram with the data
  below

Activity label Duration(weeks) Immediate predecessors
a 1
b 2 a
c 5 a
d 3 a
e 2 b
f 2 e
g 4 f, c, d
b) Determine the TPT and the critical path and
activity floats. c) Compute the EETs, LETs and
slack for every node in the AoA ESTs, LSTs,
EFTs, LFTs in the AoN diagram.
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Solution AoA
Float 0
2 b
2 e
2 f
Float 0
Float 0
Slack 0
Slack 0
1 a
5 c
4 g
T. float 1 F. float 1
Float 0
Float 0
Slack 0
Slack 0
Slack 0
Slack 0
3 d
0
T. float 3 F. float 3
TPT 11 CP a-b-e-f-g
Slack 3
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Solution AoN
0
0
0
0
1
3
TPT 11 CP a-b-e-f-g
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Example 3
3
2 b
5
3 e
5
1
2
5
7
5 c
0
2
2 a
8
14
1 f
0
2
14
8
4
6
4 g
0
2
12
3 d
2 h
5
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1. Calculate the EETs and LETs.
2. Create a precedence table (with task, duration,
   immediate predecessor, total and free floats).

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Solution
Activity Duration Total float Free float
a 2 0 0
b 2 0 0
C 5 1 1
d 3 3 3
e 3 0 0
f 1 5 5
g 4 0 0
h 2 0 0
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Readings

• Lockyer Gordon (2005) Chapter 14.

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Thanks for the attention!