Managing Project Scheduling
What is Project Scheduling?
• The process of:
– defining project activities
– determining their sequence
– estimating their duration
• Scheduling activities are part of project time
management
Types of Project Schedules
• The Gantt or bar chart
• The Critical Path Method (CPM)
• The Program Evaluation and Review Technique
(PERT)
• The Graphical Evaluation and Review Technique
(GERT)
Leading Project Teams: The
Basics of Project
Management and Team
Leadership, 2e by Anthony T.
Components of Project Schedules
• Activities—project tasks
– Any activity that will take time and resources
• Dependencies
– How one task depends on another to start or finish
Leading Project Teams: The
Basics of Project
Management and Team
Leadership, 2e by Anthony T.
Sequencing
• Requires:
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–
–
–
–
Identification of any project technical constraints
Safety or efficiency considerations
Environmental politics
Availability of required resources
Completion of prerequisite processes
Scheduling Process Steps
1. Creating a work breakdown structure (WBS) to
identify required project components
2. Defining the activities needed to complete each of
these components
3. Determining the most efficient sequencing order of
these components
Schedule Development & Usage
• Schedule developed during initiation or planning
stage
• Followed and updated during the execution stage
• Used for project tracking during control stage
Project Schedule Modifications
• Why?
– Business environment changes
• Internal – change of strategic objectives
• External – reaction to competitor actions
– New technologies become available
– Reaction to unforeseen events
Cone of Uncertainty
Project Estimation…fact or fiction
1. Accurate estimates are possible
2. Objective of estimating is to determine the end date
3. Estimate and commitment are the same
4. Historical data is an accurate indicator of productivity
5. Assigning more resources will speed up development of
system
6. A defect-free system is possible given adequate time
Components of Project Schedules
• The project network
– The arrangement of project tasks to one another
• The critical path
– The sequence of tasks within a project network that
determines how long a project will last
• Slack or float
– The amount of time a task can hold off starting without
affecting the project’s finish
Leading Project Teams: The
Basics of Project
Management and Team
Leadership, 2e by Anthony T.
Project Scheduling
• Impacted by:
– Technologies
• New and sophisticated software
• Advancements in networking and web capabilities
– Team processes
• Resource availability
• Resource allocation
• Resource assignment
– Scheduling creation and execution
• Developed early
• Followed/monitored/changed throughout project
• Assist in determination of progress
Developing a Network Diagram
• Review and revise time estimates
– Best guess (optimistic and pessimistic)
• Determine dependencies
– Which tasks depend on others to be done
– Which phases depend on others
Leading Project Teams: The
Basics of Project
Management and Team
Leadership, 2e by Anthony T.
Developing a Network Diagram
• Construct the network of project activities
• Gantt charts are done on a project calendar
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–
–
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Each task is represented by a bar
Length of bars = length of task time
Placement = dependencies
Arrows show dependencies
• Determine the critical path
Leading Project Teams: The
Basics of Project
Management and Team
Leadership, 2e by Anthony T.
Activity Sequencing
• Network diagram: a schematic display that illustrates
the various activities (or tasks) in a project as well as
their sequential relationships
• Sequential or parallel activity development
Possible Sequencing Constraints
• Technical requirements and specifications
• Safety and efficiency
• Preferences and policies
• Resource availability
Developing a Network Diagram
• Develop a WBS
in
outline form
– Arrange them
from major
to minor,
component tasks
1.0
Physical Plant
1.1
1.1.1
1.1.2
1.2
1.2.1
1.2.2
1.2.3
1.2.4
1.2.5
Prepare Plant
Rev/Rev Plans
Gut Existing Space
Dev. Infrastructure
Framing
Electrical/Wiring
Plumbing
Dry Wall
Finishing
Leading Project Teams: The
Basics of Project
Management and Team
Leadership, 2e by Anthony T.
Network Diagram
Network Diagramming Methods
• Precedence diagramming method (PDM)
• Boxes and arrows
 Boxes represent project activity (called nodes)
 Arrows represent relationships among activities
• Arrow diagramming method (ADM) or Activity on
Arrow (AOA)
 Arrows represent project tasks or activities
 Boxes represent milestones
Task Relationships
Arrow Diagramming Method
(ADM)
Network Diagram
in Microsoft Project
Additional Activity Type & Time
Relationships
• Mandatory dependencies
– Related activities that cannot be performed in parallel
• Discretionary dependencies
– Relationships of activities based on preference of the
project manager
• External dependencies
– Relationship of project activities and external events
Additional Activity Type & Time
Relationships (cont.)
• Lead Time
– Time required by one task before another task can begin
• Lag Time
– Amount of time delay between the completion of one task
and the start of the successor
Components of Project Schedules
• Lag times
– The amount of time a project task must “rest” to be
completed
• Lead times
– How far a dependent task can “lead” the completion of a
prior task on which it depends
• Milestones
– Important events in a project’s life
Leading Project Teams: The
Basics of Project
Management and Team
Leadership, 2e by Anthony T.
Using the Output of a Project Schedule
• Visualizing the project as a whole
– Project phases
– Project dependencies
• Communicating with stakeholders
• Revising the project plan
– Planning phase
– Execution phase
• Command and control
Leading Project Teams: The
Basics of Project
Management and Team
Leadership, 2e by Anthony T.
Questions?