What are Level of Effort (LOE) activities? The article was written to provide full understanding to the subject of LOE activities and how they should be managed and used. The situations described in Section 1 of this document are quite common. The problem often lies around the User’s understanding of how the tool works. One must understand fully to gain the full benefit and flexibility of the scheduling tool. Section 5 will itemize some of the misconceptions that need to be corrected when dealing with Level of Effort activities.

1. Primavera Scheduling
Tips and Tricks 02-13
What is Schedule Level of Effort (LOE)?
Here’s a common planning & scheduling situation:
The Contractor’s scheduler was tasked to resource load the schedule using
the Level of Effort activities or LOEs.
He spent several hours assigning the links but could not seem to control
the start and end date of the LOE bars. He could not understand what’s
wrong. He has done the same thing in an older version of Primavera
scheduling tool (V3.1) and it worked perfectly well.
“An LOE is a Hammock, that’s what they are” he said to himself.
I think it is about time we help this guy out.
2013
Rufran C. Frago, P. Eng., PMP®, CCEC, PMI-RMP®
Revision 3: June 28, 2013

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Author: Rufran C. Frago, P. Eng., PMP, CCEC, PMI-RMP
TABLE OF CONTENTS
PAGES
1.0 SITUATION/PROBLEM........................................................................................... 3
2.0 RELATED TOOLS .................................................................................................... 3
3.0 DEFINITION ........................................................................................................... 3
4.0 PROBLEM ANALYSIS (PA)....................................................................................... 4
5.0 EXPLANATION/SOLUTION ..................................................................................... 4
6.0 REFERENCES.......................................................................................................... 6
7.0 ADDITIONAL READING MATERIALS ....................................................................... 6
8.0 FOOD FOR THOUGHT............................................................................................ 6
9.0 ILLUSTRATIONS ..................................................................................................... 7
10.0 INDEX.................................................................................................................... 8

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Author: Rufran C. Frago, P. Eng., PMP, CCEC, PMI-RMP
1.0 SITUATION/PROBLEM
1.1 Two schedulers were arguing about the LOE and Hammock. One said
they are the same while the other one said, they are quite different.
1.2 The Lead Planner looked at the P6 schedule he prepared with his Boss
and decided to use the LOEs for resource leveling. They worked on it
for the next two days but the leveling process just won’t work. “What
is the problem here?” asked the Project Manager.
1.3 The Contractor’s scheduler was tasked to resource load the schedule
using the LOEs. He spent several hours assigning the links but could
not seem to control the start and end date of the LOE bars. He could
not understand what’s wrong. He has done the same thing in an older
version of Primavera scheduling tool (V3.1) and it worked perfectly
well. “An LOE is a Hammock, that’s what they are” he thought.
2.0 RELATED TOOLS
2.1 Project Management (Primavera 6.1 SP1, 6.2, 6.7 SP1, 6.7 SP2 and
higher)
3.0 DEFINITION
3.1 The term “User” in this document is the person using the Primavera
scheduling tool. He can be the planner, the scheduler, the Project
Manager or anyone.
3.2 A Level of Effort activity has a duration that is determined by its
dependent activities. Administration-type activities are typically
assigned as Level of Effort.

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Author: Rufran C. Frago, P. Eng., PMP, CCEC, PMI-RMP
4.0 PROBLEM ANALYSIS (PA)
4.1 The situations described in Section 1 of this document are quite
common. The problem often lies around the User’s understanding of
how the tool works. The proper logic to follow is that if one is an
equipment operator who thought that a reverse control lever is drive-
forward lever, then he/she will be in a lot of trouble. The same applies
to using Primavera. One must understand fully to gain the full benefit
and flexibility of the scheduling tool.
4.2 Section 5 will itemize some of the misconceptions that need to be
corrected when dealing with Level of Effort activities. Note that LOE is
a common term that up to now has always been misunderstood.
5.0 EXPLANATION/SOLUTION
5.1 Rules to follow when dealing with Level of Effort activities.
5.1.1 A level of effort activity's duration is dependent on its
predecessor and/or successor activities. Administration type
activities are typically assigned as Level of Effort.
5.1.2 Level of effort activities cannot have constraints assigned to
them. So, those who wanted to constrain an LOE…Forget it!
Even if you want it, it will not let you.
5.1.3 Here’s one for you. The Level of effort activity is not included
when leveling resources. You might think that it plays a role
when doing automatic leveling but they don’t. Only
resources loaded against normal task activities are included.
5.1.4 If an activity with an Actual Start is assigned to a Level of
Effort activity before being scheduled, the Original Duration
of the Level of Effort will be 0. For more information on this
see Oracle Primavera Solution ID: prim40131 "Why is the
Level of Effort (LOE) activity showing an Original Duration
(OD) of zero (0)?"

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Author: Rufran C. Frago, P. Eng., PMP, CCEC, PMI-RMP
5.1.5 Users should use level of effort activities for on-going tasks
that depend on other activities. For example, you could
assign level of effort activities for clerical work, a security
guard, or even some aspects of project management.
5.1.6 A level of effort activity is similar to but different from a
hammock activity.
5.1.7 A level of effort activity uses its assigned calendar to
summarize its dates. Hammocks are not scheduled using their
own calendar.
5.1.8 Any type of relationship can be assigned to a level of effort
activity. Only a start-to-start and finish-to-finish relationship
can be assigned to a hammock activity.
5.1.9 All finish to start and start to start predecessors and start to
finish and start to start successors drive the start date of the
LOE activity.
5.1.10 All finish-finish and start-finish predecessors and finish-start
and finish-finish successors drive the finish date of the LOE
activity.
5.1.11 A hammock activity's duration is calculated from the earliest
early start of its predecessors to the latest early finish of its
successor activities.
5.1.12 Schedule calculation of a normal activity is affected by its
“Duration Type” setting (i.e. Fixed Duration and Units/Time,
Fixed Duration and Units, Fixed Units/Time and Fixed Units).
The work effort required to complete the activity does not
change. The calculation rules do not change for an LOE
activity.

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Author: Rufran C. Frago, P. Eng., PMP, CCEC, PMI-RMP
6.0 REFERENCES
6.1 Help, About Primavera, Project Management (Primavera), V6.1 SP1,
V6.1 SP2, V6.7 SP1, V6.7 SP2 and higher.
6.2 Oracle Primavera Solution ID: 2003821145529
7.0 ADDITIONAL READING MATERIALS
7.1 Oracle Primavera Solution ID: prim40131
8.0 FOOD FOR THOUGHT
8.1 It’s been said, time and again but I will have to underline it one more
time. A level of effort activity is similar to but different from a
hammock activity.
8.2 The New User should practice linking the LOEs to controlling activities
described in Section 5.1.9 and 5.1.10 and as demonstrated in Section
9.0 Illustrations, Figure 1 and Figure 2.

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Author: Rufran C. Frago, P. Eng., PMP, CCEC, PMI-RMP
9.0 ILLUSTRATIONS
9.1 Figure 1
Links that DRIVES THE START DATE of the LOE activity
9.2 Figure 2
Links that DRIVES THE FINISH DATE of the LOE activity

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Author: Rufran C. Frago, P. Eng., PMP, CCEC, PMI-RMP
10.0 INDEX
“Duration Type” setting 5
“User” 3
ADDITIONAL READING MATERIALS 6
DEFINITION 3
FOODS FOR THOUGHT 6
hammock 6
ILLUSTATIONS 7
INDEX 8
Links that DRIVES THE FINISH DATE 7
Links that DRIVES THE START DATE 7
PROBLEM ANALYSIS 4
REFERENCES 6
RELATED TOOLS 3
resources 4
SITUATION/PROBLEM 3
SOLUTION 4
User’s understanding 4