creative ways to keep "level of effort" (ie overhead) items that take a long time but not critical away from your critical paths

just add another filter and make sure you select ALL

filter 1. critical

filter 2. longest path

filter 3.

where activity type does not equal LOE

• P6 calculation of float and longest path break under resource constraints as documented by Oracle and many others.[6][7]
• P6 does not include Level of Effort (LOE) activities when leveling resources and this can be another source of error as there is no assurance all resources are leveled.

[6] P6 -What are critical path activities?

[7] “Longest Path Value” – TomsBlog

It is common practice to assign same support resource(s) to several activities. Usually the support resource is assigned with variable quantity and workload to the hammock and to other activities with fixed quantity and fixed workload. These resources must be leveled taking into account all activities or the schedule might be unrealistic.

Please click following thumbnail (Resource A is the Project Engineer)

Hi John,

Let's say some of these Level of Effort (LOE) items are Preliminaries and General items that are recurring throughout the life of the project e.g. maintenance of site office. Why not make the Activity Type = Task Dependent AND % Complete Type = Physical. That way you have complete control over the remaining duration and % complete to match the QS method of measurement.

I've had clients insisting to use Activity Type = Task Dependent AND % Complete Type = Duration *shakes head* and at the end of the day ask why P&Gs are on the critical path without realising the Scheduler has their hands tied behind their back not being able to adjust the remaining durations due to the % Complete Type = Duration. It is possible to miss a month of site office maintenance, after all.

EDIT:

Oh my bad, reading back your post I think you were just referring to your Task Dependent activities that were "Level of Effort"-nature type activities.  

It depends on how did you define the "level of effort" activity including the link (predecessor and successor). If your "level of effort" activity (i.e. overhead) is very high level and link from start and finish of the project then it will be selected as longest path but if the “level of effort” is broken into more detail such as stages, phases, discipline then it will not be selected as longest path.

I’m not sure where you get the understanding of longest path/ critical path definition, and you mention that “the Definition of Critical Path has been changing & the AACEI definition is different than the PMI definition.” For me AACEi & PMI definition of Critical Path / Longest path are the same. If you read AACEi 49R-06 – Identifying Critical Path & PMI Practice Standard for Scheduling, both best practice standards have the same meaning of Longest Path/ Critical Path. For me, my understanding of Longest Path is the path from the start of the Project to Finished of the Project comprised with all the scope without any distortion of constraint and in compliance with CPM methods.

Sometimes the schedules are driven by constraints and distort the CPM calculation which resulted to broken Longest Path and created a false critical activity showing zero float. These needs to be reviewed thoroughly and investigate if the critical path is real and true driver of the schedule.