Critical Path Analysis

1. PRO J EC T MA NAG E M E NT -
C R I T I CA L PATH A NA LYS I S
A L E V E L B U S I N E S S S T U D I E S
S P R I N G F I E L D I N T E R N AT I O N A L S C H O O L
J A D E H A N S E N

2. WH AT I S C R I T I CA L PATH A NA LYS I S ?

3. • As mentioned in the video critical path analysis contributes to lean production.
• It is also aimed at reducing wastage and trying to do things in the most efficient way
Explanation of the aims:
1. To plan complex operations - used in the London Olympics and and other large events
2. To illustrate the order of activities - in what sequence do we need to do things
3. To identify when an activity can commence - when can a business start projects and
continue certain tasks
4. To identify critical activities - which activities are critical and need to be done as soon
as possible
5. To identify opportunities to reallocate resources - If we know certain activities are
critical we can reallocate the resources from activities that are less critical such as
machinery, labour and working capital. It may shorten the activity time and make it
more efficient.

4. WH Y D O WE N E ED TO KN OW TH ES E
N E TWO R K D I AG RA M S ?

5. Network diagrams: The diagram used in critical path analysis
that shows logical sequence of activities and the logical
dependencies between them - and the critical path can be
identified.
There are 3 reasons as to why we need to know these
network diagrams:
1. We may be asked to construct a network diagram.
2. We may be asked to make changes to an existing network
diagram.
3. We may be asked to interpret the information on a
network diagram.

6. H OW TO C O N S T RU C T A N E TWO R K
D I AG RA M -

7. • A = Activity reference letter
• Number at the bottom is how long the activity will
last (generally days or weeks)
• Nodes are start point and finish points
• 0 means no delay
• EST - earliest start time = the earliest an activity can
begin
• LFT - latest finish time = the latest an activity will end

8. H OW TA S KS A R E L I N KED

9. • 1 - starting point
• A & B = simultaneously
• All activities need to be finished to be able
to start activity D
• Node at the end to show that it is the
finished point of the project

10. WH AT I S EA RL I ES T S TA RT T I M E ?

11. Earliest start time: refers to the earliest possible time an
activity can begin without reducing the duration of any of
the preceding activities.
Calculate?
EST of next activity = EST from previous activity + duration
Rule 1 - left to right

12. WH AT I S LATES T F I N I SH T I M E ?

13. Latest finish time: The time by which a portion of
a project must end
Calculate?
LFT of last activity = LFT of activity - activity
duration
Golden rule - right to left

14. WH AT I S F LOAT T I M E ?

15. Float time: Float is any spare time that we might
have in our network
Example:
For a business, we want to think about how we
use resources during those activities that have
float. So we could take resources away and put
them elsewhere to actually reduce the length of
the whole project.

16. H OW D O WE CA LC U LATE F LOAT
T I M E ?

17. Float time = Last finished time of activity —
activity duration — Earliest start time
• If there is float time then this shows that
those certain activities are not critical. However
if there is no float time then this is a critical
activity.

18. A PP L I CAT I O N O F F LOAT T I M E

19. • Any delay on any of the critical activities will
alter that latest finish time.
• These red lines show us that none of these
activities can be delayed. If there were any
changes in any of these activities the whole
project would fall behind.

20. A DVA NTAG ES & D I SA DVA NTAG ES

21. Advantages:
1. Minimise our loss of time to maximise efficiency and use of time. We can
work out which activities happen simultaneously and again which activities we can
actually do simultaneously or move resources around from to improve our use of
time.
Disadvantages:
1. So if you have a number of factors that your trying to account for. It may
lose accuracy. If one or two activities aren’t aren’t calculated properly then it can
throw the whole project out of time
2. Reliability may be an issue and biased judgements
3. Good communication in making sure it will work. All functions need to make sure
they work together properly
4. A project which was seven years in advance or a project that has never been
undertaken by a business before are likely to have less reliable information. Also
thinking about who is making the CPA should be taken into consideration as there
may be some biased

22. Overall, critical path
analysis is a widely-used
project management tool
that uses network analysis
to help project managers
to handle complex and
time-sensitive operations.
This analysis can be a big
advantage to businesses
that have large
operations.
Thank you.