and Constructing Analyzing the Project Network Diagram
Chapter 6
CSSE 372 22.Sep.2008
Outline
Definitions Starts Critical path Slack MR Activity
What is a network diagram?
"A pictorial representation of the sequence
in which the project work can be done." What is needed to construct diagram?
Tasks Task Duration Earliest time to start task Earliest expected completion date for the
project
Uses
Planning Implementation & Control
Types
Task-On-the-Arrow (TOA)
Precedence Diagramming Method (PDM)
Using PDM
Using PDM (cont.)
Starts...
CotD
Constraints
Technical
Discretionary Best-practices Logical Unique
Management Interproject Date
Putting it together...
Forward pass
Backward pass
Using PDM
ID: Number from WBS E: Duration Work forward: ES: Earliest Start Predecessor? ES = Efpre + 1 No pred? ES = 1 EF: Earliest Finish ((ES + E) One Time Unit) Work backward: LF: Latest finish Last task? LF = EFCalculated Not last? Min(LSea. succ.) - 1 LS: Latest start ((LF E) + One Time Unit)
Critical path what is it?
"The longest duration path in the network
diagram"
"The sequence of tasks whose early
schedule and late schedule are the same"
"The sequence of tasks with zero slack or
float"
The Critical Path Determines the Completion Date of the Project
How do you calculate it?
Add up all of the path's durations
The longest one is the critical path
Compute slack
Slack = - LF EF
0 0 1 4 0 0
How do you calculate Critical Path?
Compute slack
Two types of slack Free slack amount of delay for a task without causing a delay in the early start of immediate successor task(s) Total slack amount of delay for a task without delaying the project completion date
Schedule compression
Management reserve
Padding task duration
Individual task level Project level
Bad at the task level BUT, good at the project level
Accounts for risk Incentive (management reserve time not
used can be the basis for bonus)
Coming up!
Plus/delta feedback Please turn in at end of the hour
Add your estimate of how much time you're spending per
week, on the bottom of the form
Microsoft Project Bring your laptops with this installed on Thursday, we'll use it in class
In Thursday's Angel files an example project, WBS word
document, and mpp proje...