the critical path – precedence diagram method luise lorenz christina mohr
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The Critical Path – Precedence diagram method
Luise LorenzChristina Mohr
Critical Path Method (CPM)Project planning technique
Important tool for project management
For any project with interdependent activities
CPM helps you figure out:
how long a complex project will take to complete
which activities are critical◦those needed to be done in time in
order to follow the schedule
The model of CPM
1. A list of all activities required to complete a project
2. The duration of each activity has to be known
3. Analyze the dependencies between the activities
The model of CPMCPM calculates the longest path of
planned activities to the endEarliest and latest date that each
activity can start and finishAvoiding extension of the projectDetermining the ‚critical‘ activitiesActivities which have ‚total float‘
(delayed without making the project longer)
Critical pathSeries of project network activities which
lead to the longest overall durationShortest time to complete a projectDelay of critical activity has an impact
on the completion dateShorten the planned critical path by ‚fast
tracking‘ (more activities parallel) or ‚crashing the critical path‘ (shortening activities by adding resources)
Precendence diagram method (PDM)
Network diagram uses boxes to represent activities
Connection with arrows to show the dependencies
Early / late start dateEarly / late finish dateDuration
Advantages of PDMFinding the critical pathDefining the amount of time
requiredUsage to crash projectsTo reduce resourcesDefining dependenciesIdentifying lead and lag times
Design I
Operation Description
ES(Earliest Start)
EF(Earliest Finish)
Float
LF(Latest Finish)
LS(Latest Start)
Ref. No.Duration
if the float equals zero it‘s
considered critical
Design II
ES
LF
EF
LS Float
Duration
Operation Description
if the float equals zero it‘s
considered critical
Example
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