Physical ProgressThere are three different methods of
calculating the actual progress of activities:Duration Percent
Complete,Units Percent Complete, and Physical Percent Complete. The
first two are explained in the previous articles and this article
will cover the last one, Physical % Complete.We will also discuss
the ways of choosing the appropriate percent complete field in
later articles, and will now focus on the nature and calculations
only.The Concept of Physical ProgressThe progress of some
activities is not measured appropriately by the means of duration
or units. In such cases, we use the concept of physical
progress.The physical progress of an activity is a manually-entered
value determined by the user. The value can be based on either of
these two:On physical parameters that are not applicable inside the
plan the amount of concrete poured, the length of the pipes laid
down, and the number of light bulbs installed, are examples of this
kind. You can always use resources to implement these parameters,
but they are not usually the only assignment (you also have human
resource assignments, equipment assignments, etc.) and in such
cases, theUnits % Completewill be calculated based on a combination
of the main parameter and all other assignments of the activity,
which is not your desired result. So, you can measure this kind of
progress by resource units and Units % Complete, only when that
resource is the only one assigned to the activity. Otherwise,
implementing these parameters will not be easy in an automated
system and entering them manually is usually preferred.On expert
judgement based on the physical progress of the final product or
result sometimes the physical parameters (as described before) are
not suitable basis for progress measurement and expert judgement is
preferred.Either way, physical progress is determined outside the
schedule.Two Types of Physical Progress in Primavera P6There are
two methods of dealing with physical values in Primavera
P6:Entering them manually; this is the default method and is done
by entering whatever you wish in the Physical % Complete field of
the activity.Using Activity Steps; this is done by selecting
predefined manual values.These two types are explained below.Using
Activity StepsOne of the measurement methods, also described in the
Earned Value Management for determining the earned value, is using
activity steps. Imagine an activity: designing the foundation of
the equipment xyz.Its common for the progress of activities related
to designto follow steps instead of incremental values; for
example:0%for not-started activities and those that are not
completed and issued yet80%for the completion and the first issue
of the design100%for the approved designSo we will have the
following progress curve for the sample activity:
The first issue and the approval in this sample are usually
called Activity Steps, or Progress Steps. One way of implementing
this method is to limit ourselves to only entering these values;
e.g. do not enter any physical progress before the design is
issued. By the time we issue the design, we can enter 80% as the
physical progress and again, we wont increase it until it is
approved, which makes our physical progress 100%.Primavera P6 has a
feature which makes this kind of progressing easier. We can define
the activity steps and use them for entering progress and thus to
update Physical % Complete on the activitiy. This will prevent us
from making mistakes by automatically limiting us to the predefined
values.The first thing to do is to get the settings right or
specifically the setting which enables progress via activity
steps.1) Click on the Projects item of the Enterprise menu to open
the Projects window.
2) After selecting the project in the upper part of the window,
theActivity percent complete based on activity stepsoption should
be activated to enable the activity steps. From now on, you cannot
enter manual physical % complete values for the activities which
have defined steps. However, its still possible to enter manual
values for activities whichdo not have steps. So, dont worry too
much about this setting; you can always keep it active.The next
thing to do is to define steps for the activities. The following
screen shows a plan with two activities.
The activityA1is selected. The settings we will deal with are in
theSteps Tabof the Details pane. If you dont have the pane, select
View| Show on Bottom| Details. If you dont have the Steps tab,
right click on a tab and select Customize Activity Details then
activate the Steps item.Now, it is time to define steps. Our sample
steps are 80% progress for the first issue and the remaining 20%
for the approval.3) To add a new step, click on theAdd
button(bottom-left corner of the screen).
4) Enter the name of the step and repeat clicking on the Add
button and entering the names for the rest of the steps.
Now the two sample steps have been entered. These steps have the
same weight now; each will increase Physical % Complete by 50%.5)
In order to define other weights, right click on the Step Name
heading (or any other headings) and selectCustomize Step Columns.
By this, a dialog box opens and theStep Weightcolumn can be added
to the layout.
6) Now predefined progress of each step can be entered in
theStep Weightcolumn as shown.
Now we are finished defining the steps for activity A1.You might
have many activities with the same steps. In this case, select all
steps of activity A1 (click on a step, then press Ctrl+A keys to
select all), then right click on a blank space of the steps pane
and selectCreate Template. By this, the following dialog box
appears:
Enter a desired name (General Design Steps in this sample) and
click on the OK button. Now a saved template for these steps is
created and available for further use.Now lets select activity
A2.
7) This activity is supposed to have the same steps as activity
A1. We can use the previously made template to create them. Click
on the Add From Template button and the following dialog box will
appear.
8) Double click on the General Design Steps item to
continue.
The same steps are added to the activity.Entering Physical %
Complete1) The first thing is to select the activity, go to the
Status tab of the Details pane, check the Started checkbox, and
mark the activity as started. This means that the activity is
started and ready to receive its physical progress.
2) In this example, the activity A3 is marked as started. This
activity does not have steps, so the Physical % Complete can be
entered manually. Simply click on the cell and enter the value.
For those activities which have steps (A1 and A2 in this
sample), you cannot enter manual values and should use the steps
instead (only if you have activated the steps as described in the
beginning of this very article). In order to do so, go to the Steps
tab of the Details pane after marking the activity as started. Just
check theCompletedcheckboxes of the completed steps.
Physical % Complete for WBS ElementsWBS elements usually roll-up
the information of their underlying activities; e.g. the cost of a
WBS element is the sum of the costs of its children and its Start
is equal to the minimum of the starts of its children. The way each
value is rolled-up depends on the type and nature of the value and
even some of them do not accept roll-ups by their nature.
ThePhysical % Completeis one of those fields that arenot rolled-up,
because its based on external parameters, unknown to the software,
and there is no way of equalizing them and providing a
summarization.The thing you should have in mind is that you are not
supposed to use activity percent completes for the WBS elements,
even if they have rolled-up values (like Duration % Complete and
Units % Complete). The suitable field for this purpose is
Performance % Complete which will be discussed in later
articles.SummaryThe concept of the Physical % Complete is
straightforward. Its a way of entering manual progresses based on
expert judgment or other external factors. These values can be
dynamically determined in each control period or follow a
predefined set of values (activity steps).One last thing you should
have in mind is that the planned progress, which is provided by
theSchedule % Completeand planned value fields, does not
incorporate steps and is based on dates and units (seeSchedule %
Complete articlefor more information). This can cause some amounts
of false variation between your actual progress and planned
progress. These variations are usually too little to be taken into
consideration. But if you believe they are large for your project
or you want to be as precise as possible, you should avoid activity
steps and decompose the activity into more simple activities which
are possible to be tracked based on duration or units.Final NoteAn
interesting use of Physical % Complete is that you can have
appropriate Global Changes in place, which calculate progresses and
put them in the field. Suppose you have more than one resource
assigned to each activity and are supposed to use one of them for
the progress. An appropriate Global Change can calculate the value
automatically and enter it in the field. Another example is when
you need aDuration Percent Completesimilar to that of Microsoft
Project, which is based on the At Completion Duration instead of
Original Duration. You can have another Global Change to calculate
this value and present it as Physical % Complete.
The Concept of UnitsAs explained in the previous article on the
Duration % Complete, there are three percent complete fields for
each activity: Duration % Complete Units % Complete Physical %
Complete.Weve already coveredDuration % CompleteandSchedule %
Complete. This post will explore Units % Complete and future posts
will continue to cover Physical % Complete, Activity % Complete and
finally, Performance % Complete.Each assigned resource and assigned
expense creates units in Primavera P6. The number of units depends
on duration of the activity and your current settings. However,
Units % Complete is only depended on labor and nonlabor units;
material units and expense units are not used in calculating Units
% Complete.Assignments which create units: Resource assignments
Labor Resources are used to calculate Units % Complete Nonlabor
Resources are used to calculate Units % Complete Material Resources
arenotused to calculate Units % Complete Expense assignments
arenotused to calculate Units % CompleteIf you are familiar with
the Microsoft Project, it might help to say that P6s units are
similar to MSPs work, and P6s Units % Complete is similar to MSPs %
Work Complete.The Formula Used for Units % CompleteThe Primavera P6
uses a simple and intuitive formula for Units % Complete of
Activities with labor or non-labor assignments:[Units % Complete] =
[Actual Units] / ([Actual Units] + [Remaining Units] )Actual units
is the sum of the labor units and nonlabor units, and remaining
units is equal to the sum of the remaining labor units and
remaining nonlabor units.It simply shows that how much of the units
are actualized so far. The following figure shows a sample
calculation.
As you can see in the previous figure, when the units are not
distributed uniformly, the resulting Units % Complete will not be
equal to the ratio of the actual duration to the total duration.The
next animated figure shows the values of a sample activity in
different times. We assume that the amount of the actual units in
each period is equal to the planned value of that period.
However, the above assumption is only for demonstration purposes
and actual values are not usually equal to the planned values in
the real world and even the At Completion Duration might change
regularly.The following figure shows a sample executing which does
not follow the plan. The redistribution of the units is based on an
imaginary tracking method and you should not worry about that; the
only purpose of this figure is to show the calculation of Units %
Complete with changing values.
Units % Complete VS. Duration % CompleteThere are two major
differences between Units % Complete and Duration % Complete: When
units are not distributed uniformly, the Units % Complete will not
be uniform relative to the time passed. The next figure compares
these two percent complete types in a sample activity. Duration %
Complete is calculated by the Original Duration, which can be
different from At Completion Duration (see previous article
onDuration Percent Completefor more information), but the Units %
Complete is calculated by the current and At Completion values.
Because of this, even if you have uniform units, the Units %
Complete might not be equal to the Duration % Complete. If your
units are uniform and you keep your Original Duration equal to the
At Completion Duration, then your Duration % Complete and Units %
Complete would be the same.
Thus, the Duration % Complete is suitable for uniform and
less-complicated work. Usually the more you decompose your
activities, the less complicated they will be. You also need
resource allocations to use Units % Complete.Units % Complete for
WBS ElementsThe previous explanations were for activities Units %
Complete. This field is calculated in the same way for WBS
Elements. However, I recommend you set appropriate percent complete
types and Earned Value settings and then use Performance % Complete
for the WBS Elements instead of Units % Complete and Duration %
Complete.SamplesNow that you know the formula behind the Units %
Complete, lets have a final review by looking at some sample
screenshots of the Primavera P6.
This plan has only one activity. This activity has three
resources, two labor and one nonlabor resource. Each assignment has
32 units. One assignments curve is Early Peak, another is At Start
and the third ones curve field is empty, which is equal to uniform
distribution.Lets open the Activity Usage Spreadsheet in
bottom:
Here we can see the amount of units planned for each period. Now
assume that one day is passed according to plan. I check the Actual
Start checkbox of the activity, reschedule it for the second day,
and input 3 days for the Remaining Duration. This would be the
result:
As you can see, we have some actual units in the first day and
some remaining units in the remaining three days. Calculate the
parameters based on the data from the above figure:Actual Units =
38.4h+8.0h = 46.4hRemaining Units = 14.9h+8.0h+8.0h+8.0h+2.7h+8.0h
= 49.6hUnits % Complete = 46.4h / (46.4h+49.6h) = 48.33%Now lets
put the Gantt chart away and check the Units % Complete field in
the table:
The current Units % Complete is, as we calculated before,
48.33%, which is much higher than the current Duration % Complete
(25%). Thats because our units were not uniform. We can check the
units distribution in the Activity Usage Profile view:
The above figure shows the distribution of the Labor units.
Nonlabor units are shown in the next figure:
Aggregation of these two profiles is still front loaded, which
causes the Units % Complete to have a higher value in the first
day.SummaryThe Units % Complete is one of the three types of
activity progress fields, besides Duration % Complete and Physical
% Complete. You should select suitable percent complete type of
each activity and its value will be reflected in Activity %
Complete. This value will be aggregated based on many settings and
preferences and shape the final output: the Performance % Complete.
Performance % Complete is the final field, used for actual
progress.