The document provides instructions and information for evaluating critical path methods (CPM) in project management. It includes examples of making network diagrams to identify the critical path of a project. Key steps are listing tasks, determining their order and relationships, and calculating earliest and latest start/finish times to find which tasks have zero float and define the critical path. The document discusses advantages like efficient scheduling and disadvantages like needing accurate time estimates. It also examines the Titanic project and where planning went wrong.
3. Objectives
By the end of the lesson you will……..
• Be comfortable evaluating the use of CPM in a project
• Be confident designing a network diagram
• Be able to identify the CPM by looking at a network diagram
4. • Write down every task you need to do and how long it will take
• Now list them in order
• Are there any tasks that you can do at the same time?
• Now create a flow diagram from left to right (use flip chart)
• Identify your critical path
• How long will the whole process take?
Think about the process you have to go through to make a
cup of tea for 1 person who takes milk and sugar and likes it
to be made in a tea pot
5. Put water in kettle
and switch on
Wait for kettle to boil
(3mins)
Pour boiled water
into empty teapot
Wait 3mins for tea to
mast
Pour tea into
prepared cup
Add sugar Stir sugar into tea
Take sugar bowl out
of cupboard and place
on bench next to cups
Take spoon out of
drawer and put next
to sugar bowl
Take cup out of
cupboard (10secs)
Take milk out of
fridge
(5secs)
Pour milk into cup
(10secs)
Take teabag out of
caddy
(5secs)
Empty tea pot (5 secs)
Put teabag in tea pot
(2 secs)
6. Put water in kettle and
switch on
(5secs)
Wait for kettle to boil
(3mins)
Pour boiled water into
empty teapot
(5secs)
Wait 3mins for tea to
mast
(3mins)
Pour tea into prepared
cup (5secs)
Add sugar (5secs)
Stir sugar into tea
(3secs)
Take sugar bowl out of
cupboard and place on
bench next to cups
(5secs)
Take spoon out of
drawer and put next to
sugar bowl (5secs)
Take cup out of
cupboard (10secs)
Take milk out of fridge
(5secs)
Pour milk into cup
(10secs)
Take teabag out of
caddy
(5secs)
Empty tea pot (5 secs)
Put teabag in tea pot (2
secs)
8. Project information:
Scope – To paint a red equilateral triangle
on the wall of every room in the college
Time- 1 hour
Quality- Red equilateral triangle
Cost- Budget £10
Price List:
• £1 per person
• £7 Red Paint
• £1 Blue Paint
• £1 Paint Brush
• £1 Measuring tape
Extra Information:
• It would take 1 person 10 hours to complete the project.
Activity
In groups I want you to look at the
following and decide how you would
run this project
9. Project 1
1 person Time= 10 Hours
Red Paint Quality = Red Equilateral Triangle
Paint Brush Cost= £10
Measuring Tape
Project 2
10 people Time= 1 Hour
Red Paint Quality = Red Equilateral Triangle
Paint Brush Cost= £37
Measuring Tape
Project 3
10 people Time= 1 Hour
Blue Paint Quality = Blue Equilateral Triangle
Paint Brush Cost= £31
Measuring Tape
Project 4
10 people Time= 1 Hour
Red Paint Quality = Red Triangle
Paint Brush Cost= £27
Project 5
5 people Time= 2 Hours
Red Paint Quality= Red Equilateral Triangle
Paint Brush Cost= £22
Measuring Tape
Project information:
Scope – To paint a red equilateral triangle on
the wall of every room in the college
Time- 1 hour
Quality- Red equilateral triangle
Cost- Budget £10
Price List:
• £1 per person
• £7 Red Paint
• £1 Blue Paint
• £1 Paint Brush
• £1 Measuring tape
Extra Information:
• It would take 1 person 10 hours to
complete the project.
10. What is the critical path method?
How do you find the critical path?
• A network diagram to establish the earliest time to complete a
project.
Characteristics of a activity on the critical path?
• 0 Float time (can’t be delayed without delaying the project)
• Always the longest route from start to finish
11. How to create a network diagram?
1. List all the activities needed to be completed for the project
2. List in a logical and chronological sequence
3. Find all the relationships between the activities (what depends on
another activities completion?)
4. What are the 2 types of relationships? 1= 2=
5. A realistic network diagram will contain both
13. Forward Pass=
EFT= EST+D
If there are two or more activities going into one is it the Highest or Lowest EFT that
becomes the next activities EST?
Backward Pass=
LST= LFT-D
If there are two or more activities going into one is it the Highest or Lowest LST that
becomes the next activities LFT?
Float=
LST-EST or LFT-EFT
Completing the node
14. Parallel Activities
Activity A
Activity C
Activity Duration
A- Walls 14
B- Plumbing 7
C- Electrics 5
D- Plastering 8
Activity D
EST D EFT
Activity
LST F LFT
Backward Pass- LST= LFT - D
Float= LST – EST/ LFT - EFT
Forward Pass- EFT= EST + D
Activity B
15. Go over the activity
What did you find the easiest about critical path?
What did you find the hardest about critical path?
• Did anyone find the critical path?
• Did anyone successfully complete the network diagram?
16. Activity- Machine A & Machine B
Making the network diagram……….
How I made the network diagram?
How to decide what order the sequence of activities goes in?
17. Activity Proceeded by Duration
A None
B None
C A
D A
E C
F D,E
G F
H F
I H
J B,G,I
K J
L J
18. Complete the activity
• I want you to complete the network diagram for both machines
• Find the duration of both projects and state which machine is the best to
use?
• What is the critical path for Machine A & Machine B?
20. Critical Path Advantages
• Help to increase efficiency of how time and resources are managed
• It enables time scales for the project to be planned (However initial
evaluations of each activity need to be done beforehand)
• It enables scheduling of tasks to take place in a logical order
• It means that one task isn’t held up because its predecessor wasn’t
started on time
• It helps cash flow to be monitored and extra funds to be released
when required
• It reduces waste (Time, cost, quality)
22. Critical Path Disadvantages
• It needs a skilled person to complete it in the first place
• Usefulness may be limited in very large scale or complex projects
• Accurate estimates of time are required
• Reliant on technology
• Not very portable (Can’t easily take them to the site of the project)
23. Titanic Re-visited
• Ship of luxury not speed
• Virtually unsinkable
• Take out the competition through 3 ships 3rd funded by 1st 2 and 75% revenue was from
1st class.
• 48 to 16 lifeboats due to interfering with 1st class view 1178 lifeboat places for up to
3600 guests
• Olympic had many problems and pulled staff off titanic to fix it therefore titanic was way
behind schedule yet ordered to not be a day late for launch
• Sea trials were cut from 8 weeks to half a day
• Interest was lost in titanic so to generate interest back into the launch they claimed to
beat Olympics time to New York.
• Race towards iceberg alley slowly navigate through then race off afterwards
• 53 millionaires on board
24. Titanic
• What went wrong with the project planning?
• Critical Path?
• Were activities on the critical path delayed?
25. Titanic
Was the PM aware of the project management model triple constraint?
He was obsessed with the ship being built for quality (some sacrifices in quality
were needed but not willing to be met) Binoculars, lifeboats etc. were sacrificed
but at the cost of the project.
Was unwilling to accept a change in time (Delay the launch)
Needed to keep costs at a minimum due to Olympic and 3rd ship business strategy
(Could have employed more staff to cover whilst working on Olympic)
The scope of the project was changed at many times throughout the project
By not accepting a change or being aware of the affect it would have the project
was doomed to failure.
26. Critical path for your event
• Think of all the activities needed to be done for your events?
• What order do they need to be done in?
• Can you create a sequence for the activities?
• Then create a network diagram?
• Can you identify the Critical path for your event?
27.
28. 0 5 5
Activity A
0 0 5
5 6 11
Activity C
16 11 22
5 7 12
Activity B
15 10 22
5 17 22
Activity D
5 0 22
22 3 25
Activity E
22 0 25
25 8 33
Activity F
25 0 33
What is the critical path?
29. 0 1 1
Activity A
0 0 1
1 2 3
Activity C
2 1 4
1 3 4
Activity B
1 0 4
1 1 2
Activity D
3 2 4
4 2 6
Activity E
4 0 6
6 1 7
Activity F
8 2 9
6 3 9
Activity G
6 0 9
What is the critical path?
30. 0 8 8
Activity A
0 0 8
8 6 14
Activity C
12 4 18
8 8 16
Activity B
9 1 17
8 7 15
Activity D
8 0 15
14 5 19
Activity F
18 4 23
22 11 33
Activity H
23 1 34
16 6 22
Activity E
17 1 23
15 4 19
Activity G
15 0 19
19 15 34
Activity I
19 0 34
What is the critical path?
31. 0 8 8
Activity A
0 0 8
8 6 14
Activity C
12 4 18
8 8 16
Activity B
9 1 17
8 7 15
Activity D
8 0 15
14 5 19
Activity F
18 4 23
22 11 33
Activity H
23 1 34
16 6 22
Activity E
17 1 23
15 4 19
Activity G
15 0 19
19 15 34
Activity I
19 0 34
How many days would the project be
delayed by if?
1. C is delayed by 3 days?
2. D is delayed by 4 days
3. E is delayed by 7 days
4. H is delayed by 1 day
33. Draw a network diagram for……..
ACTIVITY PROCEDED BY
A -
B A
C A
D A
E B
F C
G E
H F
I G,H
J D,I
K J
L K
34. Draw and complete this network diagram…..
ACTIVITY PROCEDED BY DURATION
A - 1
B A 2
C B 2
D C 3
E C 4
F D,E 3
G F 1
1.What is the duration of the project?
2.What is the critical path?
Notas do Editor
PM and Stakeholders have a clear direction of the project
Cant enhance one without changing another
Find where the priority of the project lies
Helps with decision making throughout a project
Project 3
10 people Time= 1 Hour
Blue Paint Quality = Blue Equilateral Triangle
Paint Brush Cost= £31
Measuring Tape
Project 4
10 people Time= 1 Hour
Red Paint Quality = Red Triangle
Paint Brush Cost= £27
Project 5
5 people Time= 2 Hours
Red Paint Quality= Red Equilateral Triangle
Paint Brush Cost= £22
Measuring Tape
