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Chapter 6: Project Time Management - Coggle Diagram
Chapter 6: Project Time Management
Importance of Project Schedules
Managers often
cite delivering projects
on time as one of their biggest challenges
Time has the least amount of
flexibility
; it passes no matter what happens on a project
Schedule issues
are the main reason for conflicts on projects, especially during the second half of projects
Individual Work Styles and Cultural Differences Cause Schedule Conflicts
One dimension of the Meyers-Briggs Type Indicator focuses on peoples’ attitudes toward structure and deadline
Some people prefer to follow schedules and meet deadlines while others do not (J vs. P)
Difference cultures and even entire countries have different attitudes about schedules
Project Time Management Processes
Planning schedule management
Defining activities
Sequencing activities
Estimating activity resources
Estimating activity durations
Developing the schedule
Controlling the schedule
Planning Schedule Management
The project team uses expert judgment, analytical techniques, and meetings to develop the schedule management plan
A schedule management plan includes:
Project schedule model development
The scheduling methodology
Level of accuracy and units of measure
Control thresholds
Rules of performance measurement
Reporting formats
Process descriptions
Defining Activities
An
activity
or
task
is an element of work normally found on the work breakdown structure (WBS) that has an expected duration, cost, and resource requirements
Activity definition involves developing a more detailed WBS and supporting explanations to understand all the work to be done so you can develop realistic cost and duration estimates
Activity Lists and Attributes
An
activity list
is a tabulation of activities to be included on a project schedule that includes
the activity name
an activity identifier or number
a brief description of the activity
Activity attributes
provide more information such as predecessors, successors, logical relationships, leads and lags, resource requirements, constraints, imposed dates, and assumptions related to the activity
Milestones
A
milestone
is a significant event that normally has no duration
It often takes several activities and a lot of work to complete a milestone
They’re useful tools for setting schedule goals and monitoring progress
Examples include obtaining customer sign-off on key documents or completion of specific products
Milestones should be (
SMART
)
Specific
Measurable
Assignable
Realistic
Time-framed
The five key points of using project milestones
Define milestones early in the project and include them in the Gantt chart to provide a visual guide
Keep milestones small and frequent
The set of milestones must be all-encompassing
Each milestone must be binary, meaning it is either complete or incomplete.
Carefully monitor the critical path
Sequencing Activities
Involves reviewing activities and determining dependencies
A
dependency
or
relationship
is the sequencing of project activities or tasks
You must determine dependencies in order to use critical path analysis
Three types of dependencies
Mandatory dependencies:
inherent in the nature of the work being performed on a project, sometimes referred to as hard logic
Discretionary dependencies:
defined by the project team., sometimes referred to as soft logic and should be used with care since they may limit later scheduling options
External dependencies:
involve relationships between project and non-project activities
Network Diagrams
Network diagrams are the preferred technique for showing activity sequencing
A
network diagram
is a schematic display of the logical relationships among, or sequencing of, project activities
Two main formats are the arrow and precedence diagramming methods
Arrow Diagramming Method (ADM)
Also called activity-on-arrow (AOA) network diagrams
Activities are represented by arrows
Nodes or circles are the starting and ending points of activities
Can only show finish-to-start dependencies
Process for Creating AOA Diagrams
(Refer Chapter 6 Slide No. 19)
Precedence Diagramming Method (PDM)
Activities are represented by boxes
Arrows show relationships between activities
More popular than ADM method and used by project management software
Better at showing different types of dependencies
Estimating Activity Resources
Before estimating activity durations, you must have a good idea of the quantity and type of resources that will be assigned to each activity;
resources
are people, equipment, and materials
Consider important issues in estimating resources
How difficult will it be to do specific activities on this project?
What is the organization’s history in doing similar activities?
Are the required resources available?
A
resource breakdown structure
is a hierarchical structure that identifies the project’s resources by category and type
Activity Duration Estimating
Duration
includes the actual amount of time worked on an activity plus elapsed time
Effort
is the number of workdays or work hours required to complete a task
Effort does not normally equal duration
People doing the work should help create estimates, and an expert should review them
Three-Point Estimates
Instead of providing activity estimates as a
discrete number
, such as four weeks, it’s often helpful to create a
three-point estimate
an estimate that includes an optimistic, most likely, and pessimistic estimate, such as three weeks for the optimistic, four weeks for the most likely, and five weeks for the pessimistic estimate
Three-point estimates are needed for PERT and Monte Carlo simulations
Developing the Schedule
Uses results of the other time management processes to determine the start and end date of the project
Ultimate goal is to create a realistic project schedule that provides a basis for monitoring project progress for the time dimension of the project
Important tools and techniques include Gantt charts, critical path analysis, and critical chain scheduling, and PERT analysis
Gantt Charts
Gantt charts provide a standard format for displaying project schedule information by listing project activities and their corresponding start and finish dates in a calendar format
Symbols include:
A black diamond: a milestones
Thick black bars: summary tasks
Lighter horizontal bars: durations of tasks
Arrows: dependencies between tasks
Adding Milestones to Gantt Charts
Many people like to focus on meeting milestones, especially for large projects
Milestones emphasize important events or accomplishments on projects
Normally create milestone by entering tasks with a zero duration, or you can mark any task as a milestone
Controlling the Schedule
Goals are to know the status of the schedule, influence factors that cause schedule changes, determine that the schedule has changed, and manage changes when they occur
Tools and techniques include
Progress reports
A schedule change control system
Project management software, including schedule comparison charts like the tracking Gantt chart
Variance analysis, such as analyzing float or slack
Performance management, such as earned value (chapter 7)
Reality Checks on Scheduling
First review the draft schedule or estimated completion date in the project charter
Prepare a more detailed schedule with the project team
Make sure the schedule is realistic and followed
Alert top management well in advance if there are schedule problems
Schedule Control Suggestions
Perform reality checks on schedules
Allow for contingencies
Don’t plan for everyone to work at 100% capacity all the time
Hold progress meetings with stakeholders and be clear and honest in communicating schedule issues
Critical Path Method (CPM)
CPM
is a network diagramming technique used to predict total project duration
A
critical path
for a project is the series of activities that determines the earliest time by which the project can be completed
The critical path is the longest path through the network diagram and has the least amount of slack or float
Slack
or
float
is the amount of time an activity may be delayed without delaying a succeeding activity or the project finish
A project team at Apple computer put a stuffed gorilla on the top of the cubicle of the person currently managing critical task
The critical path is not the one with all the critical activities; it only accounts for time (Remember the example of growing grass being on the critical path for Disney’s Animal Kingdom)
There can be more than one critical path if the lengths of two or more paths are the same
The critical path can change as the project progresses
Calculating the Critical Path
First develop a good network diagram
Add the duration estimates for all activities on each path through the network diagram
The longest path is the critical path
If one or more of the activities on the critical path takes longer than planned, the whole project schedule will slip unless the project manager takes corrective action
Using Critical Path Analysis to Make Schedule Trade-offs
Free slack
or
free float
is the amount of time an activity can be delayed without delaying the early start of any immediately following activities
Total slack
or
total float
is the amount of time an activity may be delayed from its early start without delaying the planned project finish date
A
forward pass
through the network diagram determines the early start and finish dates
A
backward pass
determines the late start and finish dates
Using the Critical Path to Shorten a Project Schedule
Three main techniques for shortening schedules
Shortening durations of critical activities/tasks by adding more resources or changing their scope
Crashing activities
by obtaining the greatest amount of schedule compression for the least incremental cost
Fast tracking activities
by doing them in parallel or overlapping them
Importance of Updating Critical Path Data
It is important to update project schedule information to meet time goals for a project
The critical path may change as you enter actual start and finish dates
If you know the project completion date will slip, negotiate with the project sponsor
Critical Chain Scheduling
Critical chain scheduling
a method of scheduling that considers limited resources when creating a project schedule and includes buffers to protect the project completion date
Uses the Theory of Constraints (TOC):
a management philosophy developed by Eliyahu M. Goldratt and introduced in his book The Goal.
Attempts to minimize multitasking
when a resource works on more than one task at a time
Buffers and Critical Chain
A
buffer
is additional time to complete a task
Murphy’s Law
states that if something can go wrong, it will
Parkinson’s Law
states that work expands to fill the time allowed
In traditional estimates, people often add a buffer to each task and use it if it’s needed or not
Critical chain scheduling removes buffers from individual tasks and instead creates
a
project buffer
or additional time added before the project’s due date
feeding buffers
or additional time added before tasks on the critical path
Program Evaluation and Review Technique (PERT)
PERT uses
probabilistic time estimates
duration estimates based on using optimistic, most likely, and pessimistic estimates of activity durations, or a three-point estimate
PERT Formula and Example refer slide chapter 6 no. 48
PERT
is a network analysis technique used to estimate project duration when there is a high degree of uncertainty about the individual activity duration estimates
Working with People Issues
Strong leadership helps projects succeed more than good PERT charts
Project managers should use
empowerment
incentives
discipline
negotiation
Using Software to Assist in Time Management
Software for facilitating communications helps people exchange schedule-related information
Decision support models help analyze trade-offs that can be made
Project management software can help in various time management areas
Words of Caution on Using Project Management Software
Many people misuse project management software because they don’t understand important concepts and have not had training
You must enter dependencies to have dates adjust automatically and to determine the critical path
You must enter actual schedule information to compare planned and actual progress