This article gives you some guidelines that you can easily put in place to follow-up the costs of your project and to estimate the remaining costs to complete. Based on the Earned Value Management, these guidelines will help you to keep your project on track, or to early warn you of potential cost deviation.
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1. Defining the Cost Baseline
This first step is probably the step that every Project
Managers performs during the project planning phase.
What are the costs that should be taken into account?
There is a hint to remember all costs for a project : THESPA. THESPA
means:
- Transfer - are there any contract, people,
assets... to transfer during the project?
- Hardware - hardware initial investment and
maintenance costs
- External - consulting and third party support
- Software - software licenses and maintenance
costs
- People - internal workload spent on the
project
- Accomodation - travel costs.
For each of these categories, you should now estimate the project costs.
- For the people category, you will of course use your
project schedule to determine the associated costs. Once you have
listed all activities and dependancies, and assigned each activity to a
resource, you can calculate the overall resource costs for the project.
To determine the Cost Baseline, you should additionnally breakdown this
resource costs by work period (we recommend to use the week as the
standard work period).
- For the Hardware, Software, External
and Transfer categories, you will also use your project
schedule to determine during which work periods these costs will be
incurred.
- For the Accomodation category, we suggest you to
estimate the total number of travel days needed for the project, and
streamline them all over the project lifecycle. You may increase the
number of travel days during given project phases, like the planning or
the execution phase, depending of the specificity of your project.
Now that you have estimated all your project costs, you should have such
a table:
Activity
|
Start week
|
End week |
Baseline |
Unit |
Unit cost |
Baseline
cost |
| PEOPLE |
|
|
|
|
|
|
1. Prestudy and Launch
|
518 |
520
|
12,5 |
man days
|
500 €
|
6250 €
|
2.1. Process Definition
|
518 |
521
|
33
|
man days
|
500 €
|
16500 €
|
2.3. Support Documentation
|
520 |
523
|
14
|
man days
|
500 €
|
7000 €
|
| |
|
|
|
|
|
|
| HARDWARE |
|
|
|
|
|
|
| Server |
530 |
530
|
30000
|
€
|
1 €
|
30000 €
|
| |
|
|
|
|
|
|
| EXTERNAL |
525 |
527
|
15
|
man days
|
900 €
|
13500 €
|
| |
|
|
|
|
|
|
| SOFTWARE |
|
|
|
|
|
|
| Licenses |
528 |
528
|
100000
|
€
|
1 €
|
100000 €
|
| |
|
|
|
|
|
|
ACCOMODATION
|
|
|
|
|
|
|
Travel days
|
518 |
518
|
2 |
travel days
|
650 €
|
1300 € |
Travel days
|
519 |
519 |
2 |
travel days
|
650 €
|
1300 €
|
Once you have detailed all project costs, it's now time to build the
Cost Baseline Graph (the famous 'S-Curve' - the graph below
shows a typical s-curve, representing the cumulated project costs in the
time).
For this you need to create an intermediate table that will sum, for
each week, the planned costs, and calculate the cumulated cost for each
week. A simple Excel graph will then enable you to generate your Cost
Baseline.
| Week |
Sum (Baseline cost) |
Cumulated Baseline Cost
|
| 518 |
7 508 €
|
7 508 € |
| 519 |
7 508 €
|
15 016 € |
| 520 |
7 958 € |
22 974 € |
| 521 |
5 875 €
|
28 849 € |
| 522 |
1 750 € |
30 599 € |
| 523 |
1 750 €
|
32 349 € |
| 525 |
4 500 € |
36 849 € |
| 526 |
4 500 €
|
41 349 € |
| 527 |
4 500 € |
45 849 € |
| 528 |
100 000 €
|
145 849 € |
| 530 |
30 000 € |
175 849 € |
Please remind that this Cost Baseline is part of the Project Plan,
therefore any change in it should be managed through the project's
integrated change process.
2. Measuring project progress
Now things begin to become difficult, because the project manager will
have to evaluate the project progress, and assess the associated costs.
The Earned Value Management method is a way to see if the project is on
time and on budget, but how can we calculate this famous 'Earned
Value'?
For this purpose you should add some columns in the first table shown
above:
- Work units already consumed (in can be man days for the People
part, but also monetary values for Hardware or Transfer
parts) (1)
- Completion rate in %. This is of course the most complex to
evaluate, especially for the activities. The PMI suggests differents
methods concerning this completion rate. Among the commonly used
methods, we suggest to chose between the 0-100 method (activity is
either non started, or fully completed) or the 0-50-100 method
(activity is 50% completed whenever it's started, and 100% when
completed).
- These two elements will enable you to compute the
'Estimate at Completion' for the related activity. If an
activity was budgeted 10 k€, that 4 k€ have already been
spent and that the activity is 50% complete, the EAC for this activity
is 4/50% = 8 k€ (2)
| Activity |
Unit
Cost
|
Baseline
|
Work done
|
%
|
Baseline
Cost
|
Actual
Cost
|
Estimate
At Compl.
|
| PEOPLE |
|
|
|
|
|
|
|
| 1. Prestudy and Launch |
500 €
|
12,5 |
29,2
|
100%
|
6 250 €
|
14 600 € |
14 600 €
|
2.1. Process Definition
|
500 € |
33 |
12,25 |
50% |
16 500 €
|
6 125 €
|
12 250 €
|
| 2.3. Support Doc. |
500 € |
14 |
2 |
15% |
7000 €
|
1000 €
|
6667 €
|
| |
|
|
|
|
|
|
|
| HARDWARE |
|
|
|
|
|
|
|
| Server |
1 € |
30 000 |
35 000
|
100%
|
30 000 €
|
35 000 €
|
35 000 €
|
| |
|
|
|
|
|
|
|
| EXTERNAL |
900 € |
15
|
0
|
0%
|
13 500 €
|
0 €
|
13 500 €
|
| |
|
|
|
|
|
|
|
| SOFTWARE |
|
|
|
|
|
|
|
| License |
1 € |
100 000
|
0
|
0%
|
100 000 € |
0 €
|
100 000 €
|
| |
|
|
|
|
|
|
|
| ACCOMODATION |
|
|
|
|
|
|
|
Travel costs
|
650 €
|
2 |
3
|
100%
|
1 300 € |
1 950 €
|
1 950 €
|
| Travel costs |
650 €
|
2 |
0 |
0 %
|
1300 €
|
0 €
|
1 300 €
|
If you repeat these calculations for each activity, you are able to add
two series in our S-curve created before : the 'Actual costs'
curve, showing the cumulation of (1) figures, and the EAC curve, showing
the cumulation of (2) figures. For this purpose, you will also need to
create an intermediate table that cumulates the AC and EAC for each work
period.
If you wish, you can also add two series in the latter graph that show:
- The baseline cost vs. the revised cost (if you experienced a
rebaselining during your project, it's interesting to keep the
initial budget curve)
- The earned value. This last curve shows the value of the work
actually done, which is different for the costs actually incurred: you
may have spent more time on an activity go get a result which has a
lower end value.
I have created an Excel sheet that shows how all this stuff works
together, and included a macro that automatically creates the above
graph. Don't hesitate to download it and reuse it for your own
project!
To download the following file, you need to preliminary register if you have no account yet.
Excel Template - Project Cost Baseline
Arnaud Bonneville, PMP
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