{{Short description|Project management technique}} The '''precedence diagram method (PDM)''' is a tool for scheduling activities in a project plan. It is a method of constructing a project schedule network diagram that uses boxes, referred to as nodes, to represent activities and connects them with arrows that show the dependencies. It is also called the activity-on-node (AON) method. * Critical tasks, noncritical tasks, and slack time * Shows the relationship of the tasks to each other * Allows for what-if, worst-case, best-case and most likely scenario
Key elements include determining predecessors and defining attributes such as * early start date * late start date * early finish date * late finish date * duration * activity name * WBS reference
Slack/Float: Determines the duration of activity delay that the project can tolerate before the project comes in late. The difference between the earliest and the latest start time.{{sfn|Kerzner|2009}}{{rp|502}}{{sfn|Sanghera|2019}}{{rp|183}} i.e. Slack = latest start date - earliest start day or Slack = latest finish time - earliest finish time.
Any activities which have a slack of 0, they are on the critical path.
thumbnail|right|solving the PDM, with: BS is an early start date. BM is a late start date. KS is an early finish date. KM is a late finish date.
Different Precedence diagram Methods * Arrow diagramming method * Project network * Critical-path method * Gantt chart * Program evaluation and review technique
==References== {{Reflist}}
== Further reading == *{{cite book | author = Kerzner, Harold | year = 2009 | title = Project Management: A Systems Approach to Planning, Scheduling, and Controlling |edition = 10th | publisher = Wiley | isbn = 978-0-470-27870-3| author-link = Harold Kerzner }} * {{cite book | last = Sanghera| first = Paul | year = 2019| title=PMP in Depth |edition = Third | publisher = Apress | isbn = 978-1-4842-3910-0 | doi=10.1007/978-1-4842-3910-0 | language=en-US}}
==External links== * [http://www.betterprojects.net/2005/10/pdms-precedence-diagram-method.html Precedence Diagram Method] at Better Projects
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Category:Project management techniques Category:Schedule (project management)