Earned Value Management (EVM) is an integrated system of
project management and control which enables a Contractor and
their customer to monitor the progress of a project in terms
of integrated cost, schedule and technical performance
measures. The EVM system is created, owned and managed by the
Prime Contractor, however the customer may have full and
timely visibility of the information contained within it. From
the a customer perspective this means that there is greater
equality of information between the Contractor and the
customer, something which is fundamental to true partnering.
Traditional project management practice tends to compare
actual costs with planned expenditure, and confuses actual
costs with actual progress. Actual costs are not necessarily a
good measure of progress. CMMI Ltd advocates maintaining a Cost to
Completion Spreadsheet or Project Schedule. EVM provides
a third reference point which is an objective view of the
status of the Contract, i.e. the value to the end goal of the
work completed to date. This can be compared with both the
planned expenditure and the actual costs to determine the
performance to date and to give early indications of problems.
EVM may also be used to enhance cost Forecasting, risk
management and as the basis for payment against the Contract.
Required Data
In order for
EVM to be implemented the Contractor must have a validated
system that can accurately measure the following three
fundamental factors:
-
The planned costs
known as the Budgeted Cost of Work Scheduled (BCWS)
-
The
actual cost of the progress made, known as the Actual Cost
of Work Performed (ACWP)
-
The earned value,
known as the Budgeted Cost of Work Performed.
At
the heart of EVM is the Work Breakdown Structure (WBS). The WBS
is a product oriented family tree of all of the goods and
services to be supplied. It is a consistent and visible
framework that displays and defines the products as elements
that relate to the end product.
The WBS needs
to be defined down to at least the level at which EVM reporting
will be applied. Care should be taken, however, in selecting
this level; too low will create an overload of data; too high
could lead to the masking of some vital information. Most
projects will find 3-4 levels within a WBS will adequately meet
their data requirements, however, large complex systems, such as
a ship, may require to go to level five or six.
The schedules that are produced for the lower elements the WBS
should be planned to the greatest possible detail, such that
the resulting activities are of manageable duration and can be
assigned to a single part of the organisation (short, sharp
activities are best).
Earned value is based on assigning a value at the activity
level to the achievement of project work. Ideally, achievement
is determined non-subjectively, on the basis of milestones and
deliverables, and is based on the planned cost (in money or
hours) of achieving that milestone. There are a number of
Earned Value techniques that can be applied to activities and
specialist advice should be sought on which is the most
appropriate to any particular activity. These activities
are grouped and controlled in a Control (sometimes called
Cost) Account (CA). This CA coincides with the level at which
EVM reporting will be applied. Each CA has a dedicated manager
appointed. This individual is empowered to plan and deliver
within time and cost constraints the work contained within the
CA.
Once the project is underway the contractor will start to earn
value by the commencement and completion of individual
activities. The summation of the values earned in a particular
Control Account gives the earned value of that CA to date.
Data Presentation
The
earned value is plotted against the planned and actual costs
over time. This illustrates in a very clear way the status of
the project. The simplest progress reports comprise of a basic
tabulation of the three basic data elements listed above, the
estimate at completion and the budget, and three derived data
elements, or variances, which are measured in terms of resources
such as man-hours or cost. The derived data elements are:
Cost Variance
(CV) - The difference between the planned and actual resource
usage for an element of work. A negative variance means that
more money was spent for the work accomplished than was
planned. Cost Variance is obtained by comparing actual cost
with earned value:
Cost Variance = Earned Value - Actual Cost
CV = BCWP -ACWP
Schedule Variance
(SV) - The difference between the budget and the earned value
for an element of work. Any difference is called the Schedule
Variance.
Schedule Variance = Earned Value - Budget
SV = BCWP-BCWS
Variance at
Completion
(VAC) - The difference between the total budget allocated for
a piece of work and the Project Manager’s estimate of the
actual resource cost at completion.
An
example of the way EVM data may be presented in the form of a
graph is detailed below. This can be available at the total
contract level and at all WBS levels down to the lowest level
set within the contract. There are a number of IT tools which
help with the collation and presentation of this data.
How to Use the EVM Data
These graphical representations are a useful management
information tool. For example, the above graph may represent a
project or task that appears to be underachieving in terms of
both cost and schedule. If corrective action is not taken the
project/task will be completed behind schedule and over
budget. There are a number of IT tools which are now available
to assist with the collation and presentation of the data.
As well as the derived
performance indicators mentioned above there are two measures
of efficiency which are also useful for determining the status
of the project; (a ratio of less than one implies that work is
underachieving against the plan, and above one implies better
than the plan)
Cost Performance
Index
(CPI) - How much it really costs to earn one pound of budget
or the "Value for Money" report.
Cost Performance Index = Earned Value/Actual Cost
CPI = BCWP/ACWP
Schedule Performance
Index
(SPI) - The Schedule Performance Index is the ratio of Earned
Value and the Planned Achievement.
Schedule Performance Index = Earned Value/Budget
SPI = BCWP/BCWS
All the above performance indicators are backward looking. One
of the main advantages of EVM is the ability to use the data
to predict with reasonable accuracy the future direction of
the project. This can be done in the following way;
a)
Cost - The final cost of the
project, or a sub-element of it, can be forecast using the
following formula:
Final Cost = Budgeted cost
CPI
b)
Schedule - Forecasting the
final end date requires the predetermination of a time based
Schedule Performance Index. This can be calculated as follows;
Time based SPI =
the original duration planned for the work to date
actual time expended on the work to date
Final project
duration = Planned project duration
Time based SPI
Reporting
Cycle
The reporting cycle should as a minimum tie in with the
contractors internal accounting periods (usually monthly -
although on the high risk projects the reporting cycle is
weekly). The version of the above chart should be produced for
each Control Account and the summary levels up through the
Work Breakdown Structure to the total contract level. These
charts should be updated to show the plan, the actual cost and
earned value of work performed along with any cost or schedule
variances. Any divergence from the overall critical path in
relation to each Control Account can be reviewed by the MoD
and the Contractor and the suitability of corrective action
agreed. Sub contractor performance and the status of their
activity can also be confirmed at this point. The contractor
should also be asked to produce variance reports to explain
the reasons for the deviation from the plan, and more
importantly, what corrective action will be taken. These
reports generally form the basis of the Customer/Contractor
discussions.
A word of warning
- whilst the discussion of corrective action is essential to
partnering agreements, the MoD must be mindful not to assume
the transfer back of risks which are properly the Contractor’s
to manage.
Benefits
EVM provides sound cost, schedule and technical performance
data which is at the centre of good decision making. The
benefits to project management come from the disciplined
approach to planning, the availability of metrics to show
genuine variances from the plan and an ability to accurately
forecast future performance. It therefore provides benefit to
both the Contractor and the MoD.
Some of the
relevant benefits to the customer are;
-
Objective Contract status information - or where you
really are in the Contract.
-
Access to cost data - or are you getting Value for Money.
-
A quantitative measure of the cost of any programme
slippage - how much is it really going to cost you to
continue?
-
The ability to identify new problems and trace the source
of them - where it is going right and where it is going
wrong.
-
An ability to accurately predict programme cost and
schedule - should you carry on (and what provisions need
to be made) or abandon the programme?
-
Confidence in the Contractor’s internal management system
- the customer is able to make informed judgements based
on real data.
-
A more disciplined approach to the measurement and
achievement of milestones - greater confidence that
milestones have been achieved.
-
Improved risk management - more disciplined planning
identifies and drives out more risks; accurate real time
progress information leads to a better informed risk
management system.
EVM accords entirely with the ethos of Smart Procurement by
creating a no surprise culture and a relationship whereby both
the Contractor and the MoD are working towards the same common
end goal of delivering the product.
Drawbacks
The above benefits can only be reaped if the project is
prepared to invest time and resource at the beginning to
establish baseline planning data. The amount of effort
required to implement full EVM may be large depending on the
company's previous EVM experience and/or the quality of their
existing Project Management practices. Ensure that adequate
time has been allowed by both the Contractor and the MoD to
set up the EVM system and to carry out effective training of
those individuals involved in using and analysing the EVM
data.
Applicability
EVM is applicable to all types of contracts including Fixed,
Firm and Target Cost Incentive Fee contracts, service,
manufacture and development contracts and all phases of the
project cycle (i.e. if you can plan it you can apply EVM).
Although EVM can be applied to all values of Contract, a
balance between the higher set up costs and the resultant
benefits (and not just the cost benefits) must be made.
It
is not recommended that EVM is introduced to an extant
contract unless the programme is undergoing a major revision.
EVM should be offered to the Contractor as part of the
Invitation to Tender as an essential feature of Project
Management. Where major items of defence equipment are being
procured from nations that mandate EVM (eg USA, Australia,
Canada),
the customer should seek access to data as a condition of the
Contract and consider payment via EVM metrics.
Payment Mechanisms
EVM can be used as a Project reporting tool only, or it can be
used as an incentive for the Contractor to perform within Cost
and Schedule parameters. This can either be via 100% payment
each reporting period on the value earned or via a combination
of milestone and reporting period Earned Value payments. The
latter is the more usual option as the introduction of
milestones allows a degree of payment retention to be
introduced and enables MoD to additionally incentivise
critical aspects of the programme. However, it only really
works if the number of milestones are limited to no more than
half a dozen highly critical milestones (e.g.
In-Service Date, Launch Ship, etc.)
Where it has been decided to pay on both the value earned and
milestones , it is important to determine an appropriate
balance between the two. Although there are no hard and fast
rules for the ratio for this, the milestone payment regime
must reflect the critical path and the physical completion of
the project. A minimum of 15% of the total contract price for
the key milestones is recommended with a maximum of about 30%
for most projects.
Further Information
-
BS6079 - Guide
to Project Management.
-
International
Earned Value Management Web Site
http://www.acq.osd.mil/pm
-
Defence Acquisition Organisation (Australia)
http://www.defence.gov.au/dmo/esd/evm/index.cfm
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