The Precedence Diagram Method (PDM) of defining relationships between activities is a powerful tool. Often, however, Schedulers, sometimes unknowingly, misuse the options available when defining relationships between activities.
In the illustration below, Activity “E” is assigned to “B” as a predecessor with relationship Finish-to-Start (FS) and is assigned to “F” with relationship Start-to-Start (SS).
Since “F” has a predecessor and a successor activity, it does not violate the “No Open Ends” rule. In fact, running the P6 Global filters, “Activities without Predecessors” and “Activities without Successors” will display no results.
However, since “E” is related to its only successor, “F” using SS, “E” does not effectively contribute to the CPM network. In fact, when “E’s” status is updated to “In Progress”, it essentially behaves like an “open ended” activity yet still complies with the “No Open Ends” rule.
Unfortunately, in P6, there is no Filter that can be constructed to check for “no finish side successors”. However, Zümmer checks this anomaly with Report #14 – “Activities With No Finish Side Successor”.
The converse to this issue is “Activities with No Start Side Predecessors”
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