Project Cost Control and Earned Value Management

To perform EVM calculations, you must first gather three fundamental metrics:

1. Planned Value (PV): Also known as Budgeted Cost of Work Scheduled (BCWS), this is the authorized budget assigned to work scheduled to be completed during a specific time period.
2. Actual Cost (AC): Also known as Actual Cost of Work Performed (ACWP), this represents the total amount of money actually expended to complete work during a given period.
3. Earned Value (EV): Also known as Budgeted Cost of Work Performed (BCWP), this is the value of the work actually completed to date, expressed as a percentage of the authorized budget.

Visualizing Performance

When these values are plotted on a graph, they typically follow an "S curve" shape, where spending is minimal at the start, accelerates in the middle, and tapers off at the end.

Earned value Figure 11.1: Example of PV, EV, and AC measurements over time.

Data Analysis Tools for Project Health

Once the core metrics are gathered, project managers use several data analysis tools to interpret the project's health.

Variance Analysis

Variance analysis examines the difference between the baseline and actual performance. The two most common variances are:

• Cost Variance (CV): Determines if you are over or under budget for the work completed. $\text{CV} = \text{EV} - \text{AC}$ A positive CV means you are under budget; a negative CV means you are over budget.

• Schedule Variance (SV): Determines if you are ahead of or behind the planned schedule. $\text{SV} = \text{EV} - \text{PV}$ A positive SV means you are ahead of schedule; a negative SV means you are behind.

Performance Indexes

To compare efficiency across different projects, managers use indexes. These are often more useful for forecasting than simple variances:

• Cost Performance Index (CPI): Measures cost efficiency. $\text{CPI} = \frac{\text{EV}}{\text{AC}}$ If $\text{CPI} > 1$, you are performing better than planned.
• Schedule Performance Index (SPI): Measures schedule efficiency. $\text{SPI} = \frac{\text{EV}}{\text{PV}}$ If $\text{SPI} > 1$, you are ahead of schedule.

Forecasting: ETC and EAC

Project managers must look forward to predict future outcomes. This involves calculating the Estimate to Complete (ETC) and the Estimate at Completion (EAC).

The Budget at Completion (BAC) is the total amount of PV for all work. The EAC is the expected total cost of the project at its conclusion. Depending on the situation, different formulas are used:

Advanced Analysis: TCPI and Reserve Analysis

• To-Complete Performance Index (TCPI): This calculates the cost performance required for the remaining work to meet a specific goal (either the original BAC or a revised EAC). $\text{TCPI (based on BAC)} = \frac{\text{BAC} - \text{EV}}{\text{BAC} - \text{AC}}$ If the TCPI is significantly higher than your current CPI, you may need to request a budget increase.
• Reserve Analysis: This involves monitoring contingency and management reserves to ensure there is enough funding to cover remaining risks.
• Trend Analysis: This uses historical data to determine if project performance is improving or worsening over time.

Exam Tip: When calculating TCPI, if the result is greater than 1, the remaining work must be performed more efficiently than the work completed to date to meet the budget goal.

Automation and Implementation

To manage these complex calculations, project managers often utilize a Project Management Information System (PMIS). This system automates the mathematical formulas and provides graphical representations (like S-curves) to help communicate status to stakeholders.

By combining these tools—from the foundational cost baseline to advanced forecasting like TCPI—project managers can transform raw work performance data into actionable intelligence, ensuring the project remains viable and aligned with stakeholder expectations.