Schedule
Management
Schedule Terminology & Definitions
Work Breakdown Structure (WBS)
•A deliverable oriented hierarchical decomposition of the
work to be executed by the project team to accomplish the
team mission and create the required deliverables. The WBS
defines the project scope.
Team Mission
25
Schedule Terminology & Definitions
Deliverable
•Any unique and verifiable product or result that must be
produced to complete a project. Usually the lowest level of
the WBS.
Team Mission
25
Schedule Terminology & Definitions
Scheduled Activity (task)
•A component of work performed to create a deliverable.
Team Mission
(Scope)
WBS
Activity List
(Schedule)
Task 1 Task 1 Task 1 Task 1 Task 1 Task 1
Task 2 Task 2 Task 2 Task 2 Task 2 Task 2
(Etc.) (Etc.) (Etc.) (Etc.) (Etc.) (Etc.)
26
Schedule Terminology & Definitions
Schedule Milestone
•A significant event in the project schedule, such as an event
restraining future work or marking the completion of a major
deliverable. A “measuring point”. Milestones have “0” (zero)
duration and no resource assignments.
26
Schedule Terminology & Definitions
Logical Relationships
•A dependency between scheduled activities, or between a
scheduled activity and a schedule milestone.
“Hard Logic” – Mandatory dependencies
“Soft Logic” – Discretionary dependencies
26
Schedule Terminology & Definitions
Logical Relationships
“Finish to Start” (most common)
Finish Start
26
Schedule Terminology & Definitions
Logical Relationships
“Finish to Finish”
Finish Finish
26
Schedule Terminology & Definitions
Logical Relationships
“Start to Start”
Start Start
27
Schedule Terminology & Definitions
Logical Relationships
“Start to Finish” (very rare, not available in
WSDOT project management software)
Finish Start
27
Schedule Terminology & Definitions
Precedence (Network) Diagram
A schedule diagramming technique in
which schedule activities are represented
by nodes and arrows shown the logical
relationship between activities
A D
F
B
E
C G
27
Schedule Terminology & Definitions
Critical Path
• Longest duration path through the
project network
• Activities on Critical Path are called
“Critical Activities”
• Critical activities have no float or
slack
27
Schedule Terminology & Definitions
Critical Path
• A project can have more than one
critical path
• Activities not on the Critical Path are
called “Non Critical Activities”
• To shorten the project duration, a
scheduler must modify the critical
path activities or dependencies
28
Schedule Terminology & Definitions
Float (Slack)
“Total Float” – The amount of time a
scheduled activity has that is can be delayed
or extended without affecting the project end
date or violating a schedule constraint.
Activity Total
Duration Float
28
Schedule Terminology & Definitions
Float (Slack)
“Free Float” – The amount of time a
scheduled activity has that is can be delayed
or extended without affecting the start of the
next scheduled activity in the project network.
Activity Free
Duration Float
28
Schedule Terminology & Definitions
Float (Slack)
“Negative Float” – The amount of time that by
which a critical activity (or milestone) misses
a required date.
Negative Activity
Float Duration
28
Schedule Terminology & Definitions
Critical Path Method (CPM)
A schedule network analysis technique used
to determine the amount of schedule
flexibility (float) on various network paths and
to determine the minimum project duration.
Forward Pass Backward Pass
•Late Start •Early Start
•Late Finish
A D •Early Finish
F
B
E
28 C G
Schedule Terminology & Definitions
Gantt Chart (bar chart)
A graphic display of schedule related
information. A report from the project
management program.
28
Schedule Tracking
Schedule Tracking
Actual Start – This is the date that work on
the scheduled activity actually started. In
project management software applications,
this field is called “Actual Start”
29
Schedule Tracking
Schedule Tracking
Actual Finish – This is the date that the work
on the scheduled activity actually finished. In
project management software applications,
this field is called “Actual Finish”
29
Schedule Tracking
Schedule Tracking
% Complete – This is a function of time. The
formula for this value is
Elapsed Duration / Total Duration
With current project management software
applications, this field must be greater than
“0” before a Base Cost % Complete can be
entered.
29
Schedule Tracking
Schedule Tracking
Base Cost % Complete – This is the percent
of the deliverable that has been completed.
There are several ways to estimate this based
on the deliverable.
A project performance baseline must be
defined in the project management program
before this value can be entered.
29
Schedule Tracking
Base Cost % Complete
Units Produced Method – This is the ratio of
units produced to the total specified at
completion. Units must be nearly identical.
Example:
Drilling 10 holes, 4 complete – 40% complete
29
Schedule Tracking
Base Cost % Complete
Interim Milestone (Agreement) Method –
Establish the percent of the total that is to be
represented by each milestone.
Example:
Deliverable: Traffic Signal Design
•Data Collected – 10% complete
•Preliminary Design – 60% complete
•Final Design – 90% complete
29 •PS&E – 100% complete
Schedule Tracking
Base Cost % Complete
50/50 Method – 50% complete assumed when
scheduled activity actual starts. 100%
complete when scheduled activity is actually
completed.
0/100 Method – 0% complete assumed when
scheduled activity actual starts. 100%
complete when scheduled activity is actually
completed.
30
Schedule Tracking
Base Cost % Complete
Proportional Relationship Method – This is
used when the completion of a measurable
amount of one work package indicates the
completion of another scheduled activity
cannot be easily measured. Use for
“hammock” tasks.
Example:
Project is 45% complete, Project Management
30 hammock task is 45% complete
Schedule Recovery / Schedule Compression
Schedule compression
A technique used to shorten a project
duration without reducing the project scope.
There are two methods of schedule
compression:
•Schedule Crashing
•Schedule fast tracking
30
Schedule Recovery / Schedule Compression
Schedule crashing
A compression technique in which scheduled
activity durations are modified; working day
definitions are modified; or resource
requirements are modified.
Typically will increase costs.
Activities must be “resource dependant”
30
Schedule Recovery / Schedule Compression
Schedule fast tracking
A compression technique in which activities
that would be normally done in sequence are
performed in parallel.
Fast tracking does not change resource
requirements, but modifies the logical
relationships.
Typically, fast tracking will increase project
risk.
Cannot fast track “hard logic”
31
Schedule Recovery / Schedule Compression
What-if Scenario Analysis
Asking “what-if” for each situation and how it
affects the project model.
Outcomes can evaluate the effects to project
objectives
Also used for risk planning.
31
Schedule Management
Module 3 exercise
Task D
10 days
Task A Task G
20 days 14 days
Task E
20 days
S Task B
Task H F
16 days
Task F 10 days
7 days
Task C
Task J
25 days
15 days
St-A-D-G-Fin: 44 days
St-A-E-H-Fin: 50 days Critical Path
St-B-E-H-Fin: 46 days
St-C-F-H-Fin: 42 days
33 St-C-J-Fin: 40 days
