Chapter 6 - Network Methods Flashcards
What is the AON approach to scheduling?
Activity on Node
- Each activity represented by a node
- Project represented by network of nodes that are connected by arrows and arranged in sequence as specified by immediate predecessors
What are activities in networks based on?
Work packages from the WBS
What is the main difference between PDM and AON networks?
AON assumes that a successor can commence immediately after an activity has finished
PDM shows kind of relationships between nodes, and allows the project manager to specify relationships like “5 days lag after activity for successor to start”
In terms of scheduling, what is a time-constrained project?
Project duration and completion time is fixed.
Resources are flexible. Additional resources may be required to complete the project on time
In terms of scheduling, what is a resource-constrained project?
Level of available resources fixed. Inadequate resources may delay project duration.
When working with a resource-constrained project, what is resource levelling?
The attempt to even out demands on resources by using slack on non-critical activities to manage resource utilisation
Why is it vital for a project manager to know the critical path of the project?
The critical path indicates:
- Which activities need strict enforcement
- Deadlines which are essential if the project is not to be delayed
- Which activities are non-essential and may be delayed
- Where resource scarcity can cause an activity to start after the ES time
- Which activities need to be shortened
Define the sensitivity of a network
The likelihood that the original critical path will change once the project is initiated
Is Chapter 6 mostly charts and little theory?
Yes
What are early times?
“The earliest activities can be started and finished
•Early times give only half the time information needed to create a realistic, feasible schedule
•Early times do not consider potential constraints”
What are late times?
“The latest times activities must be started or finished in order to complete project by target date
•To compute late times, start at last node in project, specify target completion, and work backwards
The late finish for an activity is based on late start for its successor.”
Quick way to determine duration of project?
Identify longest path through network from the start node to the end node
Slack times?
“Differnce between early and late times:
LS-ES or LF-EF
Represents scheduling flexibility, how much activity can be delayed/exceed expected duration”
Critical path?
“Path form start to end with LEAST total slack and longest path
Activities on CP are called critical activities
Any delay on activity on CP will delay project”
Total slack? Free slack?
“Total slack: Late times minus early times, and is the amount of time an activity can be delayed without delaying project
Free slack: amount of time an activity can be delayed without delaying at least one other activity”
