=====Die CPM Methode- Critcal Path Methode =====

Oracle Primavera implementiert im Kern die CPM Methode um den kritischen Pfad in einem Projekt zu finden.



Die wichtigsten Begriff in der Übersicht:

**Float** - Float or slack is the amount of time that a task in a project network can be delayed without causing a delay 

  * Free Float - the amount of time the selected activity can be delayed without delaying the activities that immediately follow 
  * Total Float  - amount of time the selected activity can be delayed without delaying the project's finish date


==Die Eigenschaften einer Aktivität in diesen Zusammenhang:==



|**ES** | Early start  |It is the earliest time that an activity can start |
|**EF** | Early finish |It is the earliest time that an activity can finish |

|**LS** |Late start    | It is the late time that an activity can start |
|**LF** | Late finish  | It is the late time that an activity can finish |

|**D**  | Duration     | Duration Of activities |
|**F**  | Float        | The float for an activity is the amount that its duration can slip without causing the project to be delayed |


Formel um diese Werte auf einer Aktivität bzw. der folgenden/vorherigen Aktivität zu berechnen:


|**ES** | Early start  | ES=Max(EF(activity before))+1 |
|**EF** | Early finish | ES+Duratoin of this activity -1|

|**LS** | Late start   | LS=LF-Duratoin+1 |
|**LF** | Late finish  | LF=Min(LS(activity after))-1  |

|**F**  | Float        | F = LS-ES |

===Übersicht===

Die Aktivitäten des Plans:

{{ :prod:prima:cpm_critical_path_method_for_primavera_activities_v01.png?300 | The List of activities }}


Netzwerk als einfacher Vorgangspfeil-Netzplan

{{ :prod:prima:cpm_critical_path_method_for_primavera_v01.png?600 |CPM - Critial Path}}


=== In Primavera PPM Desktop ===

In Primavera kann das dann als Gant oder Netzwerk dargestellt werden

{{ :prod:prima:cpm_critical_path_method_for_primavera_v02.png?600 |CPM in Oracle Primavera PPM Desktop }}


**Tipp:**

"Free Float" kann als kleiner schwarzer Balken dargestellt werden, im PPM Desktop auf den Button "Bars" und die Anzeige der Float Bar aktivieren


{{ :prod:prima:cpm_critical_path_method_for_primavera_float_bar_v01.png?500 | Free Float Anzeige als Balken im Gant Diagramm aktivieren - Oracle Primavera PPM Desktop }}
==== Quellen ====

Einführung

  * http://web.stanford.edu/class/cee320/CEE320B/CPM.pdf
  * https://de.wikipedia.org/wiki/Methode_des_kritischen_Pfades


Float

  * http://www.dau.mil/pubscats/ATL%20Docs/Jan_Feb_2012/Devaux.pdf