PMGT1865
Project Time, Cost
and Resources
Week 2: Project Scheduling
& CPM
Presented by
Jin Xue
LEARNING OUTCOMES
• Project Planning: Work Breakdown
Structure - WBS
• Understand the process of scheduling
• Understand different formats of
schedule
• Develop project schedule using 5 step
process & CPM
• Gantt Chart
Work
Breakdown
Structure
(WBS)
18
What is a WBS?
o The WBS is a tool for defining scope (inclusions only)
o It breaks down the deliverables into increasingly detailed
definitions of work as higher level items are ‘unpacked’to define
the lower level items within them
o The WBS will be the foundation of other plans (e.g. schedule and
budget) so it must capture everything that you are planning to do
and buy
o Twoformats:
• Indented list
• Tree structure
Example WBS– listformat
House InBlacktown
1 P hase 1: Planning
1.
2.
3.
4.
Meet with client to discuss requirements
Develop plans and submit to Council
DA approval
Engage builder
2 P hase 2: Implementation
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Site preparation
Pour foundations
Build frame
Install roof
Put up interior walls, floors and ceilings
Subcontract plumbing work Subcontract
electrical work
Install kitchen and bathroom fittings
Subcontract painting work
Subcontract landscapingwork
Conduct qualtiy inspection
Interior decorating and furnishing
Move in
3 P hase 3: Closure
1.
2.
3.
Close contracts
Conduct Post Implementation Review
Archive paperwork
Same WBS– tree format
Planning
Meet with client to discuss
requirements
Develop plans and submit
to council
DAapproval
Engage builder
House in Blacktown
Implementation
Site preparation
Pour foundations
Build frame
Build roof
Put up interior walls,
floors, ceilings
Plumbing work
Electricalwork
Install kitchen and
bathroom fittings
Pa int
Landscaping
Conduct Quality
inspection
Interior decorating and
furnishing
Move in
Closure
Close contracts
Conduct Post
Implementation Review
Archive paperwork
Group some of these
into sub-categories
under
“Implementation” to
shorten this list and
make it more
manageable....
Same WBS– more balanced structure
House in Blacktown
Planning
Meet with client
to discuss
requirements
Develop plans
and submit to
council
DAapproval
Engage builder
Implementation
Prep work
Site preparation
Pour foundations
Structural work
Build frame
Build roof
Put up interior
walls, floors,
ceilings
Internal work
Plumbing work
Electricalwork
Install kitchen
and bathroom
fittings
Pa int
Finishing
touches
Landscaping
Conduct Quality
inspection
Interior
decorating and
furnishing
Move in
Closure
Close contracts
Conduct Post
Implementa tion
Review
Archive
paperwork
WBS levels
Criteria for deciding how much detail or how many levels to put in the WBS:
Level at which a single individual or organisation can be assigned
responsibility and accountability for accomplishing the work package, and
Level at which you want to control the budget and monitor and collect cost
data during the project.
The work package is the point at which
• work activities are defined
• the timeline is formed
• resources are assigned
• control features will be developed
WBS levels
– Phase / Deliverable / Segment / Stream / Component / Stage
– ControlAccount
– Work Packages
– Activities
– Tasks
It doesn’t matter how you structure the top level of
the WBS, provided you stick to “the rules”
Project
Phase
Deliverable
Deliverable
Phase
Deliverable
Segment
Segment
Deliverable
S tream Stream
Control
Account
Control
Account
Work
Package
Activity
Activity
Work
Package
Activity
Activity
Activity
Control
Account
Work
Package
Work
Package
Stream
Control
Account
Work
Package
Work
Package
Phase
Deliverable
Deliverable
Deliverable
Why
How
WBSRules
– Each level mustcontain all the work required to achieve the level above
– No duplication of work in different categories
– No “1-within-1s” – categories containing only one activity
– Activities cannot belong to more than one parent category
– Organise the activities into categories that make sense to the team
• e.g. according to cost accounts; technical domains; phases; suppliers; etc
• chronology and resources are irrelevant here
o The schedule will organise the work chronologically
o The RAM willorganise the work according to “who doeswhat”
WBStips Project
Planning Implementation
PM during
Implementa tion
Status Reports
Team meetings,
etc
Deliverables
Work Package
1
Work Package
2
ClosureRemember to include project management work
• Planning and Closure phases, and PM during
Implementation
• Top-down or bottom-up approach
• Unpack a level by listing the items underneath
horizontally
• Begin activity descriptions with a verb – e.g. “Book
venue”
• When do you stop? Rules of thumb:
o Stop when you get to a level at which items can be
allocated to one person
o Stop at work package level if you have work
package managers on your team
o Break down lower if:
Team members need more task direction (e.g. novices)
Aportion of work is ambiguous, complex or important
Project Scope Statement
Project Name
Project Sponsor Project Manager
Date of Approval Last Revision Date
Scope Description List at high level what is the scope of the project
Project Deliverables List top deliverables of the project
Acceptance criteria List the acceptance criteria
Constraints List any constraints that could affect the project
Assumptions List any assumptions that the project is based upon
Your local council want to set up a community garden on land that has been used for
several years as a car park. The site is in poor condition and will need to be remediated
before work begins on establishing the planting beds and other facilities for the community
garden.You have been given a budget of $50,000 and the council has expressed a desire
for the garden to be available to the community for the coming summer. There is
significant community interest and the council have appointed a liaison officer who is in
contact with local volunteers who are keen to help with establishing the garden.
Develop a WBS – for the purpose of this activity develop 15-20 items in total.
Time: 15mins
Class Activity1
Developing the Schedule
After all activities have been defined, they are graphically portrayed using schedules, i.e.:
• Activity Networks
• Gantt charts
Four Factors may limit how fast a schedule can be completed:
1. Logical order
2. How long each activity takes
3. How many key resources are available at a specific point in the project
4. Imposed Dates
Activity Estimates
When estimating how long each activity will take
• The person responsible for performing the activity should help make the
duration estimate, this generates a commitment from that person and avoids any
bias
• Duration-based estimating provides just a start-time and end-time for the
activity, this is quick and simple but lacks detail for the PM to control
• Effort-based estimating starts with the number of person-hours (or days/weeks)
of effort and divides this by the number of resources assigned to the job to
calculate how long the job will take, this gives the PM much more flexibility
• Estimates should be aggressive, yet realistic
Schedules
– Schedules come in
several different formats
▪ Schedule Table
▪ Milestone Chart
▪ Network Diagram /
Precedence Diagram
▪ Gantt Chart / BarChart
Scheduling terminology
– Dependencies = things that must happen before an activity can begin
– Milestones = checkpoints along the way
– Float = the amount of time an activity can be delayed without delaying the end
date of the project (‘spare’time)
– CriticalActivities = activities with no float. If delayed, they will delay the project
completion date
– Critical Path = the chain of critical activities
Developing the schedule
5-steps to develop a Gantt chart:
Define
activities
Sequence
activities
Estimate
activity
resources
Estimate
activity
durations
Develop
the
schedule
Widely available project management software will create Gantt charts automatically
based on data such as durations, resources, etc.. But to truly understand how these
tools work (and common pitfalls with using them), it is useful to examine these
processes from first principles.
Step 1: Define activities
– Start with the WBS – it is the
foundation of your schedule (remember,
it contains everything you are planning
to do or buy)
– Select the levels at which you will plan the
schedule according to how much clarity
and control you want
– To ensure your schedule captures all the
work in the project (i.e. everything in the
WBS), select either a category item or
everything in the level below it
– Assign unique IDs to each WBS item
Define
a ctivitie s
S e quence
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Low-level = more clarity and control but
requires more effort
(i.e. planning at this level takes longer &
costs more ; but plans are more
accurate)
High-level = less clarity
and accuracy but planning
is quick and cheapMid-level =
compromise
– For each WBS item selected for scheduling, create a node
– Record the Activity ID and Activity Description in the cells indicated below
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Node
Step 2: Sequence activities
Early
Start
(ES)
Activity ID Late
Start
(LS)
Float Activity description
Early
Finish
(EF)
Duration Late
Finish
(LF)
1.01
Client meeting
Id. WBS
1 P hase 1: Planning
1.
2.
3.
4.
Meet with client to discuss requirements
Develop plans and submit to Council
DA approval
Engage builder
2 P hase 2: Construction
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
Site preparation
Pour foundations
Build frame
Install roof
Put up interior walls, floors and ceilings
Subcontract plumbing work Subcontract
electrical work
Install kitchen and bathroomfittings
Subcontract painting work
Subcontract landscapingwork
Conduct quality inspection
Interior decorating and furnishing
Move in
3 P hase 3: Closure
1.
2.
3.
Close contracts
Conduct Post Implementation Review
Archive paperwork
1.0
2
Plans
1.03
DAapproval
1.04
2.01
Site prep
2.02
Pour foundation
2.03
Build frame
2.04
Install roof
Eng. builder
2.05
Walls/floor
s /ce il
2.06
Plu mbing work
2.07
Electrical work
2.08
Plumbing
2.09
Painting
2.1
0
Landscaping
2.11
Inspection
2.12
Decorate
2.13
Move in
3
Clos ure
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule Step 2: Sequence activities
• Place the nodes in sequence according to
dependencies to develop a Network Diagram
• Where one activity can not happen before
another activity, place the dependent activity
to the right of its predecessor and draw an
arrow connecting the two nodes
• Repeat for all nodes
• Remember that an activity may have several
dependencies (several arrows leading into it)
or no dependencies
• All nodes must have at least one arrow
leading out from it (no dead- ends), except
for the last node in the network
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule Step 2: Sequence activities
Step 2: Sequence activities
– Key terms:
– Predecessors
– Successors
– Merge Activities
– BurstActivities
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
2.07
Electrical
1.01
Client Meeting
1.02
Plans to Council
1.03
DA Approval
1.04
Engage Builder
2.01
Site Prep
2.02
Pour Foundations
2.03
Build Frame
2.04
Install Roof
2.05
Walls Floors
Ceilings
2.06
Plumbing
2.08
Kitchen
2.09
Painting
2.10
Landscaping
2.11
Inspection
2.12
Decorating
3
Closure
2.13
Move In
• For each segment of your workshop case WBS, select the level at which you will develop the schedule
(high/mid/low-level).
• Remember: select either a category item OR everything within it, to ensure that you capture all the
work in the WBS. For the purposes of this activity, you should select between 15-20 items in total.
• Create a node for each WBS item selected →
• Develop the Network Diagram by placing the nodes insequence, then connect the nodes with arrows
representing dependencies
Time: 15min
Class Activity2
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Allocate resources to each activity
o Plan howmany people, and withwhat skillsets, willwork on each
activity
Requires balancing time, cost and quality
o More people with more specialised skill sets and experience
will:
▪ Finish quicker
▪ Cost more
▪ Produce a better quality product
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Step 3: Estimate resources
Id. Activity Description Resources
2.03 Build frame Builder, 3 Carpenters, materials
2.04 Install roof Builder, 4 Labourers, crane, materials
2.05 Put up interior walls, floors and ceilings Builder, 3 Carpenters, materials
2.06 Subcontract plumbing work Plumber, PM
2.07 Subcontract electrical work Electrician, PM
2.08 Install kitchen and bathroom fittings Builder, 2 Labourers, Plumber, fittings
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
– Estimate how long each activity will take to complete
– Record Effort and Duration separately
– Effort is how long the resources will be working (determinescost)
– Duration is the total amount of time taken to complete the activity, including:
o Lead time (e.g. waiting for goods to arrive)
o Lag times (e.g. waiting for approvals/decisions internally)
□ Tips for estimating activitydurations:
□ Estimates should reflect schedule risk (realistic)
□ Estimates should NOT include contingency time
□ Don’t be overly optimistic
□ Estimates should be revised regularly throughout the project
(progressive elaboration)
Step 4: Estimate durations
Step 4: Estimate durations
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Id. WBS Resources Duration
P h ase 1: P lanning
1.01 Meet with client to discuss requirements PM, architect 10 days
1.02
1.03
Develop plans and submit toCouncil
DA approval
Architect, PM 20days
60days
1.04 Engage builder PM 15 days
P h ase 2: Construction
2.01 Site preparation Builder, 4 Labourers, diggers and other equipment 3 days
2.02 Pour foundations Builder, 2 Labourers, concrete 2 days
2.03 Build frame Builder, 3 Carpenters, materials 2 days
2.04 Install roof Builder, 4 Labourers, crane, materials 1 days
2.05 Put up interior walls, floors and ceilings Builder, 3 Carpenters, materials 4 days
2.06 Subcontract plumbing work Plumber, PM 3 days
2.07 Subcontract electrical work Electrician, PM 4 days
2.08 Install kitchen and bathroom fittings Builder, 2 Labourers, Plumber, fittings 2 days
2.09 Sub-contract painting work Painter, 4 Labourers, PM, paint and equipment 20 days
2.10 Subcontract landscaping work Gardener, 2 Labourers, PM, plants and equipment 10 days
2.11 Conduct quality inspection Builder, PM 1 days
2.12 Interior decorating and furnishing Interior Decorator, furniture 3 days
2.13 Move in 4 Labourers, truck hire 2 days
P h ase 3: Closure PM 3 days
3.01 Close contracts
3.02 Conduct Post Implementation Review
3.03 Archive paperwork
• Estimate the duration of each activity (including effort, lead and lag)
• Make sure that your duration estimates reflect:
Time: 10min
Class Activity3
Define
a ctivitie s
Sequence
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Tip: use the same unit of time – e.g. days/weeks
Activity Res ources Effo rt Duration
1. Transfer activity durations into the Network Diagram
2. Conduct Forward Pass
3. Conduct Backward Pass
4. Calculate the amount of Float on each activity
5. Determine the Critical Path
6. Convert this information into a Gantt Chart
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Step 5: Develop the schedule
– Transfer activity durations into the Network Diagram
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Step 5: Develop the schedule
2.07
Electrical
4
1.01
Client Meeting
10
1.02
Plans to Council
20
1.03
DA Approval
60
1.04
Engage Builder
15
2.01
Site Prep
3
2.02
Pour Foundations
2
2.03
Build Frame
2
2.04
Install Roof
1
2.05
Walls Floors
Ceilings
4
2.06
Plumbing
3
2.08
Kitchen
2
2.09
Painting
20
2.10
Landscaping
10
2.11
Inspection
1
2.12
Decorating
3
3
Closure
3
2.13
Move In
2
– Conduct Forward Pass
– ES + Duration = EF
– Carry EF forward, becomes the ES of successors
– For merge activities, choose the highest EF of
predecessors
ES Activity Id LS
Float Activity description
Dur LFEF
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Step 5: Develop the schedule
0 1.01
Client Meeting
10 10
10 1.02
Plans to Council
30 20
101 2.07
Electrical
105 4
Start
with 1st
node,
where
ES = 0
30 1.03
DA Approval
90 60
30 1.04
Engage Builder
45 15
90 2.01
Site Prep
93 3
93 2.02
Pour Foundations
95 2
95 2.03
Build Frame
97 2
97 2.04
Install Roof
98 1
97 2.05
Walls Floors
Ceilings
101 4
97 2.06
Plumbing
100 3
100 2.08
Kitchen
102 2
105 2.09
Painting
125 20
101 2.10
Landscaping
111 10
125 2.11
Inspection
126 1
126 2.12
Decorating
129 3
131 3
Closure
134 3
129 2.13
Move In
131 2
Step 5: Develop the schedule
– Conduct Backward Pass
– LF - Duration = LS
– Carry LS backward, becomes the LF of predecessors
– For burst activities, choose the lowest LS of successor activities
ES Activity Id LS
Float Activity description
Dur LFEF
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
131 3 131
Closure
134 3 134Start with last node, where LF = EF
0 1.01 0
Client Meeting
10 10 10
10 1.02 10
Plans to Council
30 20 30
30 1.03 30
DA Approval
90 60 90
30 1.04 75
Engage Builder
45 15 90
90 2.01 90
Site Prep
93 3 93
93 2.02 93
Pour Foundations
95 2 95
95 2.03 95
Build Frame
97 2 97
97 2.04 100
Install Roof
98 1 101
97 2.05 97
Walls Floors
Ceilings
101 4 101
97 2.06 100
Plumbing
100 3 103
100 2.08 103
Kitchen
102 2 105
101 2.07 101
Electrical
105 4 105
105 2.09 105
Painting
125 20 125
101 2.10 115
Landscaping
111 10 125
125 2.11 125
Inspection
126 1 126
126 2.12 126
Decorating
129 3 129
129 2.13 129
Move In
131 2 131
Step 5: Develop the schedule
– Calculate the amount of Float on each activity
– Float = LS– ES
ES Activity Id LS
Float Activity description
Dur LFEF
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
0 1.01 0
0 Client Meeting
10 10 10
101 2.07 101
Electrical
105 4 105
0
10 1.02 10
0 Plans to Council
30 20 30
30 1.03 30
0 DA Approval
90 60 90
30 1.04 75
45 Engage Builder
45 15 90
90 2.01 90
0 Site Prep
93 3 93
93 2.02 93
0 Pour Foundations
95 2 95
95 2.03 95
0 Build Frame
97 2 97
97 2.04 100
3 Install Roof
98 1 101
97 2.05 97
0 Walls Floors
Ceilings
101 4 101
97 2.06 100
3 Plumbing
100 3 103
100 2.08 103
3 Kitchen
102 2 105
105 2.09 105
0 Painting
125 20 125
101 2.10 115
14 Landscaping
111 10 125
125 2.11 125
0 Inspection
126 1 126
126 2.12 126
0 Decorating
129 3 129
131 3 131
0 Closure
134 3 134
129 2.13 129
0 Move In
131 2 131
Step 5: Develop the schedule
– Determine the Critical Path
– Chain of activities with no float
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
101 2.07 101
0 Electrical
105 4 105
0 1.01 0
0 Client Meeting
10 10 10
10 1.02 10
0 Plans to Council
30 20 30
30 1.03 30
0 DA Approval
90 60 90
30 1.04 75
45 Engage Builder
45 15 90
90 2.01 90
0 Site Prep
93 3 93
93 2.02 93
0 Pour Foundations
95 2 95
95 2.03 95
0 Build Frame
97 2 97
97 2.04 100
3 Install Roof
98 1 101
97 2.05 97
0 Walls Floors
Ceilings
101 4 101
97 2.06 100
3 Plumbing
100 3 103
100 2.08 103
3 Kitchen
102 2 105
105 2.09 105
0 Painting
125 20 125
101 2.10 115
14 Landscaping
111 10 125
125 2.11 125
0 Inspection
126 1 126
126 2.12 126
0 Decorating
129 3 129
129 2.13 129
0 Move In
131 2 131
131 3 131
0 Closure
134 3 134
• Calculate the duration and Critical Path of the workshop case study
project
Time: 15min
Class Activity4
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
Step 5: Develop the schedule
– Convert this information into a Gantt Chart
Early
Start
Early
Finish
Float
Late
Finish
Define
a ctivitie s
Seque nce
activities
Est imate
activity
res ources
Es tima te
activity
durations
Develop the
schedule
30 1.04 75
45 Engage
builder
45 15 90
Gantt Charts
• Gantt charts, or bar charts, are popular due to their
simplicity.
• Combine two functions of planning and scheduling.
• Do not display the interrelationships of activities.
• If one activity is delayed, it is not obvious how that will
affect other activities.
• Cumbersome to make changes to the plan manually.
• Most project management software can show
interdependencies with arrows.
Questions ?