Week 1 Lecture 2 - Network Anlaysis/Project Scheduling Flashcards
What is meant by the term ‘Independent Float’? And how is it calculated?
The amount of time an activity can be delayed if the predecessor activity finishes at its Late Start Time and the successor activity must start at its Early Start Time
Independent float = Total Float (TF) - Free Float (FF)
What is meant by the term ‘Free Float’? And how is it calculated?
The amount of time an activity can be delayed without affecting the ‘Earliest Start Time’ (EST) of its successor activity
Free Float = ES (of successor) - EF (of predecessor)
What is ‘Resource smoothing and Levelling?
Smoothing:
Resources levels aren’t fixed. The main aim of smoothing is to complete as soon as possible with minimum resource fluctuation. (Soft Constraint)
Levelling:
Resources are fixed. No more can be attained (Hard Constraint)
What are the two types of resources used in a project? And what are they?
Renewable:
- Availability depends on the time.
- Activities hold resources and then release them.
Consumable:
- Activities consume resources
- Resources disappear after use
What is meant by the term ‘Crashing a project’?
Crashing involves allocating extra resources to an activity at extra cost.
By allocating extra resources to an activity in the critical path, the length of the project is reduced.
How to ‘Crash a Project’?
Asses which activity will reduce the project time by 1 unit for the lowest cost.
What must be considered when crashing a project that will help to keep overall costs down?
Choose an activity in multiple paths
An increase in activity duration of 2 weeks on an activity with 1 week total float will result in a delay of how much to project finish?
1 week
What is the formula for calculating the mean duration of each activity given the optimistic, most likely and pessimistic values?
Mean = To + 4*Tm + Tp / 6
What is the formula for calculating the variance between the durations of activities?
Variance = Tp-To / 6
What 3 forms can network relationships take?
Start to finish: (cannot finish one activity before another has started)
Start to start: (cannot start one activity until another activity has started)
Finish to Finish: (cannot finish one task until another activity has finished)
What is the ‘Lead time’ in relation to network analysis?
The amount of time activities can cross over when its possible for a second activity to start whist the first is still being completed.
What is ‘Lag time’ in relation to network analysis?
The amount of time delay between the end of one activity and the start of another.
