Administrative time gaps are rarely, if ever, accounted for in scheduling, but some consider them to be the root cause of most schedule delays. Administrative time gaps are therefore, worth discussion.
Schedules can be defined and divided into Productive Work Segments (PWS) and Time Gaps (TG). A PWS refers to the division of an activity’s duration through logic-ties. And each PWS is restrained by one or more other PWSs. TGs are imposed, intentional, delays to the commencement of PWSs.
TGs further segment into Productive Time Gaps (PTG) and Administrative Time Gaps (ATG), i.e. TGs that allow time for either productive actions or administrative actions. A PTG is a planned delay in the commencement of a PWS while waiting the completion of another PWS. An ATG is a PWS delay to allow for the completion of administrative actions, prerequisites to the respective PWS.
This article briefly introduces the concept of ATGs, and the reason they are the bane of proficient project managers.
ATGs occur in Start-to-Start (SS) relationships and Finish-to-Start (FS) relationships. Finish-to-Finish (FF) TG provide a pure PTG. This is because ATGs affect the commencement of PWSs and not the completion of PWSs. In the FF relationship both
PWS:B1 and PWS:A are restraints to PWS:B2, Figure 1. PWS:B2 is restrained by the completion of PWS:A and PWS:B1.
Figure 1
But any administrative actions required for PWS:B2 were already contained in the ATG for PSW:B1. Again, ATG are not thought to occur in the completion of an activity. One may argue however; that quality approvals at PWS completion may require administrative efforts to arrange the resources for the final inspection.
The FS relationship is most often considered to have a relationship-duration of zero. Activity B is restrained only by the prior completion of activity A. But if there are administrative prerequisites to activity B, then the FS relationship duration, in theory, will be greater than zero.
The SS has both a PTG and an ATG. Activity B cannot begin until productive work is performed on activity A, a PTG. And activity B also cannot begin until any administrative actions are executed.
Murray B. Woolf asserts in his “Faster Construction Projects with CPM Scheduling” that “virtually every activity in a Project Schedule has administrative prerequisites to its commencement”. And these ATGs are often not immaterial. The problem is that these administrative actions are “rarely delineated or their performance durations quantified”. But fundamental to any PWS are the mobilization of labor, materials, and equipment on a worksite, and, possibly, the transfer of vital information to clarify work scope. These are all administrative efforts, and they delay the commencement of any PWS.
Summary
Studies have demonstrated that most project delays link directly to administrative failures. Most activities achieve their estimated PWS durations. It is therefore not the lagging performance of PWSs that causes delays. It is the slow or unaccounted performance of administrative actions.
A takeaway from this realization is the warning that schedules with many SS and FS relationships may be accompanied by ATGs that could negatively impact the schedule. It is also noted that guidelines like the Defense Contract Management Agency’s 14-Points Assessment favor FS relationships. But these same FS relationships may be a source of administrative delays.
Glossary:
- Productive Work Segment – PWS
- Time Gap – TG
- Productive Time Gap – PTG
- Administrative Time Gap – ATG