Project Schedule

1. Project Schedule Management
Dr. Huy Nguyen

2. Project Management Framework
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3. Process Groups & Knowledge Areas Mapping
Knowledge
Areas
Process Groups
Initiating Planning Executing Monitoring & Controlling Closing
Integration
Develop Project
Charter
Develop Project Management Plan
Direct and Manage Project Work
Manage Project Knowledge
Monitor and Control Project Work
Perform Integrated Change Control
Close Project or Phase
Scope
Plan Scope Management
Collect Requirements
Define Scope
Create WBS
Validate Scope
Control Scope
Schedule
Plan Schedule Management
Define Activities
Sequence Activities
Estimate Activity Durations
Develop Schedule
Control Schedule
Cost
Plan Cost Management
Estimate Costs
Determine Budget
Control Costs
Quality Plan Quality Management Manage Quality Control Quality
Resource
Plan Resource Management
Estimate Activity Resources
Acquire Resources
Develop Team
Manage Team
Control Resources
Communications Plan Communications Management Manage Communications Monitor Communications
Risk
Plan Risk Management
Identify Risks
Perform Qualitative Risk Analysis
Perform Quantitative Risk Analysis
Plan Risk Responses
Implement Risk Responses Monitor Risks
Procurement Plan Procurement Management Conduct Procurements Control Procurements
Stakeholder Identify Stakeholders Plan Stakeholder Engagement Manage Stakeholder Engagement Monitor Stakeholder Engagement
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4. Project Schedule Management
Knowledge
Area
Process Groups
Initiating Planning Executing
Monitoring &
Controlling
Closing
Time
• Plan Schedule Management
• Define Activities
• Sequence Activities
• Estimate Activity Durations
• Develop Schedule
• Control Schedule
Enter phase/
Start project
Exit phase/
End project
Initiating
Processes
Closing
Processes
Planning
Processes
Executing
Processes
Monitoring &
Controlling Processes
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5. Project Schedule Management
• The process required to manage timely completion of the project.
• Project time management starts with planning by the project management team
(not shown as a discrete process).
• In small projects, defining & sequencing activities, estimating activity resources
& durations, developing schedule model are viewed as a single process.
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6. 1 - Plan Schedule Management
• Process of establishing the policies, procedures, and documentation for
planning, developing, managing, executing, and controlling the project
schedule.
• Work package decomposed into activities (schedule activities).
• In the real word, sometime we skip define activities since we take WBS down
to the activity level.
Inputs
1. Project management
plan
2. Project charter
3. Enterprise
environmental factors
4. Organizational
process assets
Tools & Techniques
1. Expert judgment
2. Analytical techniques
3. Meetings
Outputs
1. Schedule
management plan
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7. 1 - Plan Schedule Management
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8. Schedule Management Plan (Outputs)
• Project schedule model development;
• Level of accuracy;
• Units of measure;
• Organizational procedures links;
• Project schedule model maintenance;
• Control thresholds;
• Rules of performance measurement;
• Reporting formats;
• Process descriptions.
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9. 2 - Define Activities
• Process of identifying and documenting the specific actions to be performed to
produce the project deliverables.
Inputs
1. Schedule
management plan
2. Scope baseline
3. Enterprise
environmental factors
4. Organizational
process assets
Tools & Techniques
1. Decomposition
2. Rolling wave
planning
3. Expert judgment
Outputs
1. Activity list
2. Activity attributes
3. Milestone list
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10. 2 - Define Activities
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11. Techniques for Defining Activities
• Decomposition: Dividing and subdividing the project scope and project
deliverables into smaller, more manageable parts.
• Rolling Wave Planning: Progressive elaboration (iterative) planning where you
do not to plan activities until you start the project management process for that
phase is in the project life cycle.
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12. Outputs for Defining Activities
• Activity Attributes:
– Use for schedule development, selecting, ordering, sorting the planned
schedule activities;
– Used to identify e.g. responsible person, place, level of effort (LOE),
apportioned effort (AE).
• Milestone list:
– Milestone is a significant point or event in the project:
• Not a work activity;
• Checkpoint to help control the project;
– Additional milestones can be added in Sequence Activities & Develop
Schedule process;
– The list can indicate the level of milestones (mandatory, optional, etc).
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13. 3 - Sequence Activities
• Process of identifying and documenting relationship among the project
activities.
Inputs
1. Schedule
management plan
2. Activity list
3. Activity attributes
4. Milestone list
5. Project scope
statement
6. Enterprise
environmental factors
7. Organizational
process assets
Tools & Techniques
1. Precedence
diagramming method
(PDM)
2. Dependency
determination
3. Leads and lags
Outputs
1. Project schedule
network diagrams
2. Project documents
updates
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14. 3 - Sequence Activities
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15. Precedence Diagramming Method (PDM)
• Precedence Diagramming Method (PDM) or Activity-on-Node (AON):
– Method used in Critical Path Methodology (CPM);
– No dummy activities;
– Logical relationship:
• Finish-to-Start (FS);
• Finish-to-Finish (FF);
• Start-to-Start (SS);
• Start-to-Finish (SF).
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16. Precedence Diagramming Method (PDM) -
Applying Leads & Lags
• Use leads and lags to support realistic and achievable project schedule.
• Each activity is connected at least to one predecessor and one successor
except the start and the end.
• Leads:
– May be added to start an activity before the predecessor activity is
complete.
• Lags:
– Inserted waiting time between activities.
A B C
Predecessor Successor
A
B
A
B
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17. Precedence Diagramming Method (PDM) - Example
• Example of PDM which showing logical relationship and leads or lags:
• Other methods to draw network diagram:
– ADM (Arrow Diagramming Method) or AOA (Activity-on-Arrow);
– GERT (Graphical Evaluation and Review Technique): Allows loops
between activities.
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18. Precedence Diagramming Method (PDM) -
Dependency Determination
• To define sequence among activity, these types of dependency are used:
1. Mandatory (hard logic):
– Inherent in the nature of work being done or required by the contract or legal;
– E.g. you must design before you can develop.
2. Discretionary (preferred, preferential, or soft logic):
– Define based on knowledge of best practices;
– Can be changed if needed;
– Important when how to shorten or re-sequence the project.
3. External: Involve a relationship between project activities and non-project activities
4. Internal: Involve a precedence relationship between project activities and are
generally inside the project.
Network diagram:
• ≠ PERT (Program Evaluation and Review Technique) chart;
• Shows just dependencies (logical relationship);
• Could show the critical path if activity duration estimates added.
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19. Precedence Diagramming Method (PDM) -
Description of a Node
• Description of a node (activity, task):
– ES = Earliest Start;
– LS = Latest Start;
– EF = Earliest Finish;
– LF = Latest Finish;
– EF = ES + D - 1;
– LS = LF - D + 1;
– Float (F) = LS - ES = LF – EF.
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20. Estimate Activity Resource (Inputs, Tools & Techniques)
• Resource calendar:
– Information (skill, location, etc) in which resource (people, equipment,
material, etc) are potentially available.
• Published estimating data:
– Use company’s rates.
• Bottom up estimating:
– Activity is decomposed to be more confidence in estimating.
• Alternative analysis:
– Levels of resource capability or skills;
– Different size or type of machines;
– Different tools (hand versus automated);
– Make-rent-or-buy decisions regarding the resource.
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21. 4 - Estimate Activity Durations
• Process of estimating the number of work periods needed to complete individual
activities with estimated resources.
• Schedule shall be as believable and realistic as possible (do not allow padding).
Inputs
1. Schedule management plan
2. Activity list
3. Activity attributes
4. Activity resource requirements
5. Resource calendars
6. Project scope statement
7. Risk register
8. Resource breakdown structure
9. Enterprise environmental
factors
10.Organizational process assets
Tools & Techniques
1. Expert judgment
2. Analogous estimating
3. Parametric
estimating
4. Three-point
estimates
5. Group decision
making techniques
6. Reserve analysis
Outputs
1. Activity duration
estimates
2. Project documents
updates
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22. 4 - Estimate Activity Durations
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23. Estimate Activity Durations (Tools & Techniques)
• Analogous estimating (Top down):
– Use actual duration of previous activity (historical) that has similarity.
• Parametric estimating:
– Use statistical relationship between historical data and other variables
(e.g. learning curve);
– The result can become heuristics (experience based technique / rule of
thumb).
• Reserve analysis (buffer):
– Includes contingency reserves.
• A Buffer isn’t a Padding. A Padding is extra time added to a schedule that
you don’t really think you need but that you add just to feel confident in the
estimate. Padding is when we take a conventional approach to building a
Gantt chart, come up with three months, but tell our boss four months.
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24. • Also called Program Evaluation and Review Technique (PERT);
• Use for time and cost estimation;
• Expected activity duration (EAD), Standard deviation (SD) and Variance (V)
calculated from Most-likely (M), Optimistic (O), Pessimistic (P);
• Range of estimate = EAD +/- SD;
• Duration uncertainty = Confidence interval (CI) = P - O;
• Assuming a ± 3 sigma CI, we have:
• Standard deviation cannot be sum;
• Variance used to calculate total SD of the project.
3-Point Estimate (PERT)
Expected
6
Ο
4Μ
P 

Standard
Deviation ()
6
Ο
P 
Variance
2
6
Ο
P





 

 variance
SD
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25. Exercise: 3-Point Estimate (PERT)
• Question:
– Together with your team, you applied 3-point estimation on a critical path
which consists of two activities. The following duration uncertainties are
all calculated in assuming a ± 3 sigma confidence interval.
– The duration uncertainty - defined as pessimistic minus optimistic - of
the first activity is 18 days; the second estimate has an uncertainty of 24
days. Applying the PERT formula for paths, what is the duration
uncertainty of the entire path?
A. 21 days;
B. 30 days;
C. 42 days;
D. No statement is possible from the information given.
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26. Exercise: 3-Point Estimate (PERT)
• Answer:
– See that the question says that duration uncertainty is pessimistic minus
optimistic, in other words P - O. We know that SD is (P - O) / 6, thus SD is
“duration certainty” / 6;
– Thus:
• For path 1 : SD = 18 / 6 = 3; Variance = 3 * 3 = 9;
• For path 2 : SD = 24 / 6 = 4; Variance = 4 * 4 = 16;
– Total path variance = 16 + 9 = 25;
– Total path SD = (P - O) / 6 = Sqrt (25) = 5;
– DURATION UNCERTAINTY = P - O = 5 * 6 = 30.
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27. 5 - Develop Schedule
• Process of analyzing activity sequences, durations, resource requirements, and
schedule constraints to create the project schedule model.
Inputs
1. Schedule management plan
2. Activity list
3. Activity attributes
4. Project schedule network
diagrams
5. Activity resource requirements
6. Resource calendars
7. Activity duration estimates
8. Project scope statement
9. Risk register
10.Project staff assignments
11.Resourse breakdown structure
12.Enterprise environmental factors
13.Organizational process assets
Tools & Techniques
1. Schedule network
analysis
2. Critical path method
3. Critical chain method
4. Resource
optimization
techniques
5. Modeling techniques
6. Leads and lags
7. Schedule
compression
8. Scheduling tool
Outputs
1. Schedule baseline
2. Project schedule
3. Schedule data
4. Project calendars
5. Project management
plan updates
6. Project documents
updates
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28. 5 - Develop Schedule
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29. Critical Path (Tools & Techniques)
• Critical Path is the longest duration path;
• Identify the shortest time needed to complete a project;
• There can be more than one critical path;
• We don’t want critical path, it increases risk;
• Don’t leave a project with a negative float, you would compress the schedule;
• Near-critical path is the path that has close in duration to critical path.
• Float (Slack):
– Total float: The amount of time an activity can be delayed without delaying
the project end date or intermediary milestone;
– Free float: The amount of time an activity can be delayed without delaying
the early start date of its successor(s);
– Project float: The amount of time an activity can be delayed without
delaying the externally imposed project completion date required by
customer / management.
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30. Critical Path Method Basic (Tools & Techniques)
Activity Precedence Duration
A 2
B 3
C A 1
D B 4
E B 2
F C 1
G D, F 5
H E 2
I H 2
J G, I 0
K
• Dummy activity = 0 resource & 0 duration;
• Critical activities:
– All activities in the critical path;
– Delay in the completion of these activities will lengthen the project timescale;
– Has float = 0.
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31. Forward Pass
Backward Pass
ID
Critical Path using PDM (Tools & Techniques)
• Calculation:
– Forward Pass to calculte ES, EF:
• ES + D = ES (successor);
• Use highest value on join.
– Backward Pass to calculate LS, LF:
• LS - D (predecessor) = LS (predecessor);
• Use lowest value on join.
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32. Exercise
Questions:
• What is the critical path?
• What is critical path duration?
• What is float (slack) duration of activity A30?
Answers:
• -
• -
• -
A60
A50
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33. • The longest duration path through the project considering both activity
dependencies and resource constraints.
• Network diagram and critical path are identified first.
• Type of buffers:
– Project buffer;
– Feeding buffer;
– Resource buffer.
Critical Chain (Buffer Management) (Tools & Techniques)
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34. • Resource leveling:
– Start and finish dates are adjusted based on resource constraints with the
goal of balancing demand for resources with the available supply;
– Can be used when shared or critically required resources are only
available at certain times, or in limited quantities, or over-allocated.
• Resource smoothing:
– Adjusts the activities of a schedule model such that the requirements for
resources on the project do not exceed certain predefined resource limits;
– The critical path is not changed and the completion date may not be
delayed.
Resource Optimization Techniques (Tools & Techniques)
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35. • Analysis on effect of changes on a particular thing (assumption) on the project
which make activity duration change.
• What-if scenario analysis:
– Evaluate scenarios in order to predict their effect, positively or negatively,
on project objectives;
– “What if the situation ‘Y’ is represented by the scenario ‘X’ happens?”
• Monte Carlo simulation:
– Used when there is possibility that the critical path will be different for a
given set of project conditions;
– Using probability distribution for each activity or group of activities;
– Using computer software;
– Using three-point estimates and network diagram;
– Help deal with “path convergence”:
• Multiple paths converge into one or more activities (but adding risk).
Modeling Techniques (Tools & Techniques)
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36. • Fast Tracking:
– Performing critical path activities in parallel;
– Usually increase risk and requires more attention to communication;
– May need a rework;
– E.g. design is half finished and start coding.
• Crashing:
– Analyze cost and schedule trade-offs;
– Determine most compression for least cost;
– Crash the tasks that cost the least first, focusing on minimizing project
cost;
– Always results in increased cost.
Schedule Compression (Tools & Techniques)
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37. Project Schedule (Outputs)
• Schedule can be shown with or without dependencies (logical relationship).
• Presented as:
– Summary form e.g. Master schedule, Milestone schedule;
– Detailed form.
• Format:
– Network diagram;
– Milestone chart;
– Bar chart (Gantt chart).
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38. Schedule Data (Outputs)
• Includes at least:
– Schedule milestone;
– Schedule activities;
– Activity attributes;
– Assumptions & Constraints.
• Additional information can be added, such as:
– Resource histograms;
– Cash-flow projections;
– Order & delivery schedules;
– Alternative schedules.
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39. 6 - Control Schedule
• Process of monitoring the status of project activities to update project
progress and manage changes to the schedule baseline to achieve the plan.
Inputs
1. Project management
plan
2. Project schedule
3. Work performance
data
4. Project calendars
5. Schedule data
6. Organizational
process assets
Tools & Techniques
1. Performance reviews
2. Project management
Software
3. Resource
optimization
techniques
4. Modeling techniques
5. Leads & lags
6. Schedule
compression
7. Scheduling tool
Outputs
1. Work performance
information
2. Schedule forecasts
3. Change requests
4. Project management
plan updates
5. Project documents
updates
6. Organizational
process assets
updates
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40. 6 - Control Schedule
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41. Thank You
Next topic:
Project Cost Management
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