Introduction to Project
Management session 3
Programme
Session II Review
Homework Discussion
Introduction to Work Breakdown
Network Diagrams
Critical Path Analysis
Gantt Charts
Summary and Close
Risk Analysis
A Brief Review
Internal / External Risks
External Environment
Things outside of the projects direct control that may result in its
failure, but can be identified and monitored via a watching brief,
i.e. fire, flood, famine, pestilence, war and global economic
meltdown!
Internal Environment:
Those that can occur as part of
the project itself - something can
usually be done about these
Risk Likelihood / Impact
• How likely is the risk?
– Low, Medium, High
– Or Extremely Unlikely (will happen once in a
blue moon), Unlikely, Medium, Likely.
Extremely Likely (it’s going to happen)
Influence and Control
• Simple list of what you can and cannot
influence and control
Risk Likelihood / Impact
• What would be the impact on the project?
– Low, Medium, High
– Or Very Low (no real impact), Low, Medium,
High, Very High (catastrophic)
Constraint Risks
• Product risk
– A risk that prevents you from meeting the product
(project) specification
• Schedule risk
– A risk that prevents project element from being
completed on time
• Resource risk
– A risk that prevents enough or appropriate resources
from being available to complete a project element
Boston Chart
High Risk
Low Return
High Risk
High Return
Low Risk
High Return
Low Risk
Low Return
Project Familiarity
Both task and
setting familiar
SHOULD BE OK
Task Unfamiliar
Setting Familiar
Task familiar
Setting unfamiliar
Task Unfamiliar
Setting unfamiliar
BE WARY!
Do you still want to undertake
the project?
Homework Self Study Discussion
You:
• Reviewed your QUAD chart
• Produced a Stakeholder Analysis
• Produced a Risk Assessment
(or you should have…).
Is your QUAD chart now more precise?
Have you assessed all risks?
Have you considered all potential stakeholders?
Tool & Technique Work
Breakdown Structures
Planning the Do - The Work
Plan
Remember our Project Life Cycle
•
•
•
•
•
Conception Phase (The Idea)
Definition Phase (The Plan)
Initiation Phase (The Team)
Implementation Phase (The Work)
Evaluation Phase (The Wrap-up)
PLAN
DO
REVIEW
Motivation for a Work Plan
•
•
•
•
•
Helps you to understand what needs to be done
Helps others understand what needs to be done
Ensures that a task is not missed
Ensures that a task is not duplicated
Provides contingency should a key supporter be:
–
–
–
–
Taken off project
Long term ill
Resign
Get run down by a no 43 bus and die
“The Devil is in the Detail”
• Need enough detail for any given activity to be able to:
– Accurately estimate resources needed
– Accurately estimate the time required
– Assign the activity to someone else
• Too little detail will result in poor estimates
• Too much detail is a waste of planning time
“The Devil is in the Detail”
• Identifying the appropriate level of detail
– largely a question of experience
– best to ask an expert (i.e the person performing
the activity, not someone who used to do it 5
years ago, or the manager who doesn’t do it but
thinks they are an expert).
For a New Project
• Identify tasks by
– asking others / through consultation
– borrowing information from similar projects
• Be prepared to get it wrong and learn
– this is one of the reasons why we have post-project
evaluation.
– Even experienced project mangers get it wrong;
remember the London Dome, the Wembley stadium,
the London Millenium Bridge….
The Jigsaw puzzle model
Consider a jigsaw puzzle
it may comprise many jumbled pieces
there may only be a few pieces
you might only have one piece and need to
find the others?
you may have a nearly completed picture
picture & just need to add a few pieces
it may be complete and look like this
or could look like this
Your project is a jigsaw
• You might have a complete picture
• You might have all the pieces
• You might know where to fit them and the
sequence in which to fit them
• Or you might not….
Tool & Technique 10
Work Breakdown Structure
ELEMENTS
• So your task is to identify what level of
detail you have for your puzzle.
• You will need to do this with your team of
people.
• How accurately you do this could determine
the success, or otherwise, of the project
Breaking the puzzle down into
manageable pieces
• Called a ‘work breakdown’ structure
• There is a ‘bottom up approach’ and a ‘top
down approach’
Methods for Developing a Work
Breakdown Structure
• Bottom-up approach (using Brainstorming)
• This is the most appropriate method for projects
involving untested methods and approaches OR
where team members have not performed similar
projects before
• Brainstorm to generate all activities you can think
of that will have to be done.
• Then group them into categories
Remember the Traditional
Cooked Breakfast Project?
Group work TASK 1: Developing a
Work Breakdown Structure
Bottom Up Approach
• Brainstorm and write any and all activities that you think
need to be performed for the Proper Cooked English
Breakfast (PCEB) project on post-it notes or small cards.
Do not worry about overlap or level of detail at this stage.
– Do not discuss task wording or details
– Do not judge
– Write everything down
Group work TASK 2: Developing a Work
Breakdown Structure (Bottom-Up)
• Study the post-its or cards and group the
activities into a few major categories with
common characteristics.
– These will be your work assignments (elements)
• Can any activities within an element be
grouped into a number of subtasks?
• Note this process is sometimes referred to as
the Crawford Slip method.
Methods for Developing a Work
Breakdown Structure II
Top-down approach
• Better suited to projects with which you or
others are familiar
• Start at the top level (the finished project)
and systematically develop increasing levels
of detail for all activities
Group work TASK 3: Developing a Work
Breakdown Structure (Top-down)
• Consider the finished project and work
backwards.
• Use a top-down approach to determine any
activities that might have been missed
– There might not be any for a project of this size? ?
General rule for breaking down your
work
• No Gaps: All work for a given task must be
encompassed in its sub-tasks
• No Overlaps: The same work should not be
included in more than one sub-task.
Gantt Chart
• If we were to cut the length of each post it
note or card to scale and lay them out from
start to finish then we basically have a Gantt
Chart.
• The Gantt chart is one of the project
manager’s tools for scheduling
The Gantt Chart - example
Time (s)
Switch stove on
Break eggs
Cook sausages
Fry eggs
Pour Water
Slice + dice salad
Get cutlery
Lay table
Place Pot on Tray
Serve
breakfast served
SLACK - SLACK - SLACK - SLACK
Gantt Chart
• Named after its originator Henry Gantt.
• A Gantt chart is a bar graph which illustrates on a
timeline when each activity will start, finish and
end.
• It’s a pictorial representation of each stage of the
project showing individual tasks subdivided into
work units according to the length of time they
will take.
Gantt Chart - How to
• A graph
• Time on the horizontal axis
• Each task (preferably in sequence) is listed
on the vertical axis
• Micrsoft office assistance available at
http://office.microsoft.com/engb/products/results.aspx?qu=gannt+chart&sc=9
TIME - Project Time
?
?
Time – project time
The total time needed to perform a group or
set of activities depends on 2 things:
1 DURATION – how long each activity will
take,
2 SEQUENCE – the order in which you
perform the activities.
Project time
Note that SEQUENCE might be determined
by:
• the project
• you the project manager
• the customer/client
• all of the above
A question ?
• How long will a project consisting of 12
activities, which each take one week, take?
A 1 week
B 12 weeks
B1 exactly 12 weeks
B2 just slightly over 12 weeks
C 6 weeks
D don’t know
The answer ?
• A 1 week might be correct if we can do all 12
activities at the same time and have the resources
to do so.
• B 12 weeks (exactly or just over) might be correct
if we have to do all the activities in sequence.
• C 6 weeks might be correct if we can do activity
1&2 together, 3&4 together, 5&6 together, etc.
• D don’t know - correct! We don’t know as we
have insufficient information at the moment.
Tool & Technique
The Network Diagram
• Note when people who aren’t project
managers think of project management
techniques they usually only think of
Network diagrams and the Gantt chart.
• They are important tools, but, as we have
seen so far, they are not the only tool.
Tool & Technique
The Network Diagram
The Network diagram is a flow-chart that
illustrates;
• Dependencies between tasks
• The order in which tasks will be
performed
Network Diagrams
– Event - sometimes called a milestone
(e.g. “design begins”, “draft report
approved”)
– Activity - work required to move from
one event to another
– Span time - the actual project time
required to complete an activity
Network Diagrams (aka Dependency Diagram
aka Precedence Diagram)
• Events – take no time and consume no
resources – they occur instantaneously
• Activity – takes time and consumes
resource
• Span time - the actual time required to
complete an activity within the project
(aka duration or elapsed time)
Span Time
But before we can consider a Network
diagram we need to know about Span time
Estimating time within a project is one of
most difficult things to do
Span Time
• Span time is actual project time – its
duration.That is the time it takes to do
something within the project.
• For example an activity which takes 1week of
project time with 1 person doing it may take 3
days of project time if 2 people do it.
• Or it may still take 1 week as the activity may use
a process using a special glue which needs 72
hours to set.
Span time varies – typically
depending on
•
•
•
•
•
•
•
•
•
Resources
people,
£funds,
equipment,
technology,
environment,
time
supplier delivery times,
etc.
Span time varies
• Many things may affect an activity’s span
time – some will be under your
control….and some will not.
• One of the project manager’s most difficult
jobs is to correctly and accurately
calculate/estimate an activity’s span time –
always keeping an eye on reducing it if this
reduces the overall project duration.
Span time and work effort
• Span time is not the same as work effort.
• Work effort = the no. of hours it would take a
person to do the activity.
• Example – 4 people work 5 days to complete an
activity; the span time is 5 days, the work effort is
20 person days.
• Example – 2 people work 10 days to complete the
same activity; the work effort is still 20 person
days; but the span time is now 10 days.
Span time – an example
• You need to test run new software, you estimate
this will take 24 hours on a computer. If you are
only allowed access to the computer for 6 hours
per day, then the span time is 4 working days.
• If you want to halve the span time, then doubling,
or tripling, the number of people working on it
would have no effect; but getting access to the
computer for 12 hours per day would. The span
time has now been halved to 2 working days (not
necessarily 2 consecutive days).
Span time
• The project manager needs to decide and be
consistent as to whether his/her project’s
span time is calculated according to actual
real life working days or consecutive days.
• Do you include weekends, bank holidays, a
5% allowance for sick leave ??
Working out span time
• Need to take account of actual working hours and
practice
• Example - An activity taking 24 hours will have a
span time of 3 working days if an 9.5 hour day is
worked with a 1 hour lunch break and a 15 minute
break morning & afternoon with the assumption
that people do nothing else other than work on the
project.
• Or it could have a span time of 6 working days if
the working day is 4 hours with no breaks.
Working out span time
• It takes experience and practice.
• It’s easy to underestimate how long
something will take.
• It’s easy to assume a team member will
spend 100% of their time doing something –
in reality this very rarely occurs.
Other difficulties with estimating
time
• Hofstadter's Law
• Hofstadter's Law is a statement of the difficulty of
accurately estimating the amount of time it will
take to complete tasks of any substantial
complexity.
• It always takes longer than you expect, even when
you take Hofstadter's Law into account.
• source1999 20th aniveersary edition of Godel, Escher, Bach: An
Eternal Golden Braid
Other difficulties with estimating
time
• Optimism bias - the demonstrated
systematic tendency for people to be overoptimistic about the outcome of planned
actions.
• This includes over-estimating the likelihood
of positive events and under-estimating the
likelihood of negative events.
Other difficulties with estimating
time
• The planning fallacy - the tendency to underestimate taskcompletion times. Lovallo and Kahneman (2003) expanded
the planning fallacy from being the tendency to
underestimate task-completion times to being the tendency
to underestimate the time, costs, and risks of future actions
and at the same time overestimate the benefits of the same
actions.
• According to this definition, the planning fallacy results in
not only time overruns, but also cost overuns and benefit
shortfalls.
Other difficulties with estimating
time
• Unforeseen delays planning fallacy
• The problem with unforeseen delays is that
you can’t foresee them! When people ask
for a realistic estimate how long something
will take they envision everything going
exactly as planned, with no unexpected
delays or unforeseen catastrophes
• Possibly therefore the trick is to plan in less detail.
Elizier Yudkowsky (Oxford University blog
overcomingbias.com identifies that one way is to
ask yourself broadly how long it’s taken to do
something similar in the past
• “You'll get back an answer that sounds hideously
long, and clearly reflects no understanding of the
special reasons why this particular task will take
less time. This answer is true. Deal with it.”
Network Diagrams
Network Diagrams
(aka Dependency Diagram)
A network diagram in activity-in-thebox format is sometimes called a
Precedence Diagram
Tool & Technique 12 Activity-in-theBox Network or Precedence Diagrams
Activity 2
t2 = 1
Activity 1
t1 = 5
END
START
Activity 3
t3 = 1
Activity 4
t4 = 3
Activity 5
t5 = 2
All inputs to an activity box must have been completed before it can begin.
E.g. Activity 1 and 4 must be completed before 5 can commence. Total minimum time is 7
Remember
• Events – take no time and consume no
resources – they occur instantaneously
• Activity – takes time and consumes
resource
• Span time - the actual time required to
complete an activity within the project
(aka duration or elapsed time)
EXAMPLE
Activities & Events
An activity
– Time T=5
An Event
– Time T= 0
Write report
Finished report
approved
(Remember, events take no time)
An Activity and an event
– Time T= 5
Hand in
finished report
The 2 rules of network diagrams
• Rule 1 After you finish an activity or reach an
event you can proceed to the next activity or event
as indicated by the arrow(s) leaving that activity or
event.
• Rule 2 To be able to start an activity or reach an
event you must complete all activities and reach
all events from which arrows entering that activity
or event emanate.
Group work TASK 4: Network Diagram
• Consider one of the tasks, (e.g. “Make Tea” in
our breakfast project).
– Check to see if you have identified all sub-tasks
– Place post it notes on large sheet and attempt to
create a network diagram
– Assign estimates of the time required to perform
each sub-task
Example Activity-in-the-Box Network
Diagram (Making the Tea)
Re-Boil
10s
START
Fill
Kettle
Switch
Kettle On
Boil Water
(Initial)
Scold Pot
Put
Tea-bag In
Pour
Water
Place Pot
On Tray
10s
3s
180s
10s
5s
15s
5s
Put Milk
In Jug
Put Sugar
In Bowl
Get Tray
15s
15s
10s
Put Milk, Sugar,
Cup & Saucer on Tray
10s
Serve
20s
END
TEA
SERVED
Critical Path Analysis !
The next area we will look at – Critical Path
Analysis and Slack time is often considered by
people to be the most difficult part of project
management.
• It is logical, but appears difficult at first.
• If you use Microsoft project software then it will
‘do’ all the following for you. But it’s important to
know how to do it so that you can understand what
the software is actually doing.
Some definitions
• Critical Path – a sequence of activities in your
project that takes the longest time to complete.
• Slack Time – the maximum amount of time that
you can delay an activity and still finish your
project on time.
• Non Critical Path – a sequence of activities that
you can delay by some amount & still finish you
project in the shortest possible time.
Tool and Technique
Critical Path Analysis
• Critical Path Analysis is the process of
identifying the sequence of activities in
your network diagram that takes the longest
time to complete.
• The length of the critical path defines how
long your project will take to complete.
That is then the SHORTEST possible time
your project will take.
Example of a Network Diagram
(Activity in the box or Precedence)
Activity 2
T=1
Activity 1
T= 5
END
T=7
START
T=0
Activity 3
T=1
Critical Path is red. Time T is in weeks
Activity 4
T= 3
Activity 5
T=2
The Forward Pass
A start-to-finish analysis
Determining critical paths, non critical
paths, & earliest start and finish dates
Using ‘the forward pass’
a start-to-finish analysis
Refer to the handout of the Network
diagram
The 2 rules of Network diagrams…
• Rule 1 After you finish an activity or reach an
event you can proceed to the next activity or event
as indicated by the arrow(s) leaving that activity or
event.
• Rule 2 To be able to start an activity or reach an
event you must complete all activities and reach
all events from which arrows entering that activity
or event emanate.
Determining critical paths, non critical paths,
and earliest start and finish dates.
Consider the diagram’s upper path – activities 1 & 2
• Rule 1 says you can start on activity 1 the moment the
project starts.
• So the earliest you can finish activity 1 is the end of week
5 (you add it’s span time of 5 to it’s earliest start time of 0,
to arrive at week 5).
• Rule 2 says the earliest you can start activity 2 is the
beginning of week 6 (as the arrow from activity 1 is the
only 1 entering activity 2).
• So the earliest you can finish activity 2 is the end of week
6.
The Forward Pass
A start-to-finish analysis
Determining critical paths, non critical paths,
and earliest start and finish dates.
Consider the diagram’s lower path – activities 3, 4, 5.
• The earliest you can start activity 3 is the moment the
project starts.
• The earliest you can finish activity 3 is the end of week 1.
• The earliest you can start activity 4 is the beginning of
week 2.
• The earliest you can finish activity 4 is the end of week 4.
• BUT, according to rule 2, the two arrows entering activity
5 mean that you cannot start activity 5 until BOTH
activities 1 & 4 are finished. Even though you can finish 4
by end of week 4, you cannot finish 1 until end of week 5.
SO the earliest you can start 5 is the beginning of week 6.
A guideline
• This illustrates a general guideline:
If 2 or more activities lead to the same
activity, then the earliest date which you
can start that activity is equal to the latest of
the earliest finish dates for these 2 or more
activities.
The Forward Pass
Determining critical paths, non critical paths,
and earliest start and finish dates
•
•
•
•
•
Earliest finish date for 4 is week 4.
Earliest finish date for 1 is week 5.
SO, the earliest you can start 5 is beginning of week 6.
Earliest you can finish 5 is end of week 7.
Earliest you can finish 2 is end of week 6.
SO, the earliest you can finish the entire project & reach
the event ‘end’ is the end of week 7.
What have we just found out?
We now know that:
• The length of the project is 7 weeks – the shortest
time in which it can be completed.
• There is one critical path, it takes 7 weeks, it
includes: the event ‘start’, activity 1, activity 5, the
event ‘end’.
• Activities 2, 3, 4 are not critical paths.
Back to our example of a Precedence
Network Diagram
Activity 2
T=1
Activity 1
T= 5
END
T=7
START
T=0
Activity 3
T=1
Activity 4
T= 3
Critical Path is red. Time T is in weeks
Activity 5
T=2
The backward pass
A finish-to-start analysis
Determining slack times and earliest
start and finish dates
Using ‘the backward pass’
a finish-to-start analysis
The Backward Pass
A finish-to-start analysis
Determining slack times and
earliest start and finish dates
• We know from our start-to-finish or forward pass analysis
that it takes 7 weeks to reach the event ‘end’.
BUT, rule 2 ( To be able to start an activity or reach an
event you must complete all activities and reach all events
from which arrows entering that activity or event emanate).
says that we cannot reach the event ‘end’ until both
activities 2 & 5 are completed.
SO, if we want to finish by the end of week 7, the latest we
can finish 2 & 5 is the end of week 7.
The Backward Pass
A finish-to-start analysis
Determining slack times and
earliest start and finish dates
Consider the diagram’s lower path – activities 3, 4, 5.
• You must start 5 by the beginning of week 6, at the latest,
if you want to finish by end of week 7.
• Rule 2 says you can’t start 5 until you finish 1 & 4. SO,
you must finish 1 & 4 by the beginning of week 6 at the
latest. MEANING, you must start 4 by the beginning of
week 3.
• You must finish 3 before you can start 4, THEREFORE
you must finish 3 by the end of week 2,
• which means that you must start 3 by the end of week 2.
The Backward Pass
A finish-to-start analysis
Determining slack times and
earliest start and finish dates
Now consider the diagram’s upper path.
• You must start activity 2 by the beginning of week 7.
• You cannot start 2 until you finish activity 1. SO, you
must finish 1 by the end of week 6.
• You must finish 1 by end of week 5 in order to start
activity 5 at the beginning of week 6, and by the end
of week 6 to allow work on activity 2 to start at the
beginning of week 7. Finishing activity 1 by end of
week 5 will satisfy both requirements.
Another guideline
• This illustrates another general guideline
If two or more arrows leave from the same
event or activity, the latest date by which
you must finish the activity, or reach the
event, is the earliest of the latest dates by
which you must start the activities or reach
the events to which these arrows lead.
Confused….
• Don’t worry; most people find it confusing
at first. It takes a little time for it to fully
sink in.
• Spend time after this session reviewing the
handouts to help you understand the
process.
Back to our cup of tea…
Tool & Technique 14
Critical Path Analysis
(for Making the Tea)
Re-Boil
10s
START
Fill
Kettle
10s
Switch
Kettle On
Boil Water
(Initial)
Scold Pot
Put
Tea-bag In
Pour
Water
Place Pot
On Tray
3s
180s
10s
5s
15s
5s
Put Milk
In Jug
Put Sugar
In Bowl
Get Tray
15s
15s
10s
Critical Path
Put Milk, Sugar,
Cup & Saucer on Tray
10s
Serve
END
TEA
SERVED
20s
TOTAL TIME = TIME ON CRITICAL PATH = 253 secs
Group work TASK 5: Network Diagram
- Identifying the Critical Path
• Can you identify the critical path in your
network diagram?
– Highlight it in red
– Calculate the time-span of the critical path
– Do you have any slack in your project?
Slack time – the maximum amount of time that you
can delay an activity and still finish your project
in the shortest possible time
But what if we alter one (or more) of
the factors?
• Essentially this is why Network diagrams
are essential for project management. They
allow us to change one of the variables and
see what affect it has on the whole project.
• Microsoft Project software does it all for
you at the press of a button
But what if we alter one (or more) of the
factors?
• We can alter time the time constraint.
Change in Time constraint
• The hotel manager has decided that the tea
must be made more rapidly.
• How can this be done?
• A super-kettle is purchased that can boil
water in 10 seconds!
Tool & Technique 14
Critical Path Analysis
(for Making the Tea)
Re-Boil
10s
START
Fill
Kettle
10s
Switch
Kettle On
Boil Water
(Initial)
Scold Pot
Put
Tea-bag In
Pour
Water
Place Pot
On Tray
3s
180s
10s
5s
15s
5s
Put Milk
In Jug
Put Sugar
In Bowl
Get Tray
15s
15s
10s
Critical Path
Put Milk, Sugar,
Cup & Saucer on Tray
10s
Serve
END
TEA
SERVED
20s
TOTAL TIME = TIME ON CRITICAL PATH = 253 secs
Effect of Resource Changes
New Technology!
Re-Boil
1s
START
Fill
Kettle
Switch
Kettle On
Boil Water
(Initial)
Scold Pot
Put
Tea-bag In
Pour
Water
Place Pot
On Tray
10s
3s
10s
10s
5s
15s
5s
Put Milk
In Jug
Put Sugar
In Bowl
Get Tray
15s
15s
10s
Resource Change
Critical Path
Put Milk, Sugar,
Cup & Saucer on Tray
10s
Serve
END
TEA
SERVED
20s
TOTAL TIME = TIME ON CRITICAL PATH = 83 secs
Strictly speaking this would not work with a single person due to the overlap in activities
Gantt Chart - 2
Super Kettle
Time (s)
Fill Kettle
10
Switch Kettle On
3
Boil Water (Initial)
10
Scold Pot
10
Put Tea Bag in Pot
5
Re-boil
1
Pour Water
15
Place Pot on Tray
5
Put Milk in Jug
15
Put Sugar in Bowl
15
Get Tray
10
Place Milk, Sugar, Cup & Saucer
10on Tray
Serve
20
Tea has been served
START-FINISH TIME
83
Strictly speaking this would not work with a single person due to the overlap in activities
Cost-Benefit
• The time saved was 170 seconds
• However, the new super-kettle set you back a
princely £200
• Is the investment worth it to improve on changes
in time constraint?
• If those 170 seconds saved represented an early
finish bonus worth £300 then the investment
would be worth it.
• And once you have bought it it can be used over
and over again.
But what if we alter one (or
more) of the factors?
• We can take on another member of staff.
Effect of Resource Changes
super kettle!
Re-Boil
1s
START
Fill
Kettle
Switch
Kettle On
Boil Water
(Initial)
Scold Pot
Put
Tea-bag In
Pour
Water
Place Pot
On Tray
10s
3s
10s
10s
5s
15s
5s
Put Milk
In Jug
Put Sugar
In Bowl
Get Tray
15s
15s
10s
Resource Change
Critical Path
Put Milk, Sugar,
Cup & Saucer on Tray
10s
Serve
END
TEA
SERVED
20s
TOTAL TIME = TIME ON CRITICAL PATH = 83 secs
Effect of Resource Changes
Another pair of hands and super kettle!
Re-Boil
1s
START
Fill
Kettle
10s
Switch
Kettle On
3s
Boil Water
(Initial)
10s
Put Milk
In Jug
Put Sugar
In Bowl
Get Tray
15s
15s
10s
Scold Pot
Put
Tea-bag In
Pour
Water
10s
5s
15s
Put Milk, Sugar,
Cup & Saucer on Tray
10s
Serve
Place Pot
On Tray
5s
END
TEA
SERVED
20s
Person A
Person B
Critical Path
TOTAL TIME = TIME ON CRITICAL PATH = 78 secs = only 5s saved
Cost vs Benefit ?
• So it’s probably not worth employing
another member of staff once we have
bought our super kettle if we only save a
further 5 seconds
Gantt Chart - 3
Another pair of hands
Time (s)
Fill Kettle
10
Switch Kettle On
3
Boil Water (Initial)
10
Scold Pot
10
Put Tea Bag in Pot
5
Re-boil
1
Pour Water
15
Place Pot on Tray
5
Put Milk in Jug
15
Put Sugar in Bowl
15
Get Tray
10
Place Milk, Sugar, Cup & Saucer
10on Tray
Serve
20
Tea has been served
START-FINISH TIME
78
What Have We Done?
• Reviewed risk analysis
• Introduced work breakdown structures and
methods for their generation
– had a go at the bottom-up approach
• Described network diagrams
– activity-in-box diagrams
– critical paths, the forward pass, the backward pass
– effects of resource changes
• Gantt charts
– Slack time
Homework Self study
• 1 Review your Stakeholder Analysis, ask for other
people’s opinions and feedback. Keep a copy of
the original and then produce a modified version
which is more accurate.
• 2 Review and amend if required your Risk
Analysis or produce one using the advanced risk
analysis grid. Keep a copy of the original.
• 3 Produce a Network diagram and/or a Gantt chart
for either the whole project, or a section of it.
• Read through today’s handouts. Check you
understand it. www.hull.ac.uk/workbasedlearning/