3.4 Earned Value Management (EVM)

Earned Value Management (EVM)

Traditional project management often tracks performance by comparing actual spending to the planned budget. However, this approach is flawed because it ignores the actual work accomplished. If a project has spent 50% of its budget, is it doing well? It depends entirely on whether 20% or 60% of the physical work has been completed.

Earned Value Management (EVM) solves this problem by integrating scope, schedule, and cost. It provides an objective, quantitative method for measuring project performance and forecasting future results. EVM is a critical tool for Construction Managers overseeing complex projects.

Core EVM Concepts

EVM relies on three fundamental data points, measured at a specific point in time (the data date):

1. Planned Value (PV)

Also known as the Budgeted Cost of Work Scheduled (BCWS). It is the authorized budget assigned to the scheduled work. It answers the question: "How much work did we plan to complete by this date?"

2. Earned Value (EV)

Also known as the Budgeted Cost of Work Performed (BCWP). It is a measure of the work physically completed, expressed in terms of the budget authorized for that work. It answers the question: "How much physical work have we actually accomplished?"

• Example: If a concrete foundation has a total budget of $100,000, and it is 40% physically complete, the EV is $40,000.

3. Actual Cost (AC)

Also known as the Actual Cost of Work Performed (ACWP). It is the total cost actually incurred in accomplishing the work performed. It answers the question: "How much money have we actually spent to accomplish the work done so far?"

Variance Analysis

By comparing PV, EV, and AC, the CM can calculate variances to determine if the project is on track.

Schedule Variance (SV)

Measures whether the project is ahead of or behind schedule, expressed in dollar terms. SV = EV - PV

• If SV is positive: The project is ahead of schedule.
• If SV is negative: The project is behind schedule.
• If SV is zero: The project is exactly on schedule.

Cost Variance (CV)

Measures whether the project is under or over budget. CV = EV - AC

• If CV is positive: The project is under budget.
• If CV is negative: The project is over budget.
• If CV is zero: The project is exactly on budget.

Performance Indices

Indices convert variances into efficiency ratios, making it easier to compare performance across different projects or tasks.

Schedule Performance Index (SPI)

A measure of schedule efficiency. SPI = EV / PV

• SPI > 1.0: Progressing faster than planned (Favorable).
• SPI < 1.0: Progressing slower than planned (Unfavorable).
• SPI = 1.0: Progressing exactly as planned.

Cost Performance Index (CPI)

A measure of cost efficiency. It is often considered the most critical EVM metric. CPI = EV / AC

• CPI > 1.0: Earning more value than spending (Under budget / Favorable).
• CPI < 1.0: Earning less value than spending (Over budget / Unfavorable). For example, a CPI of 0.8 means the project is only getting 80 cents of value for every dollar spent.
• CPI = 1.0: Spending exactly matches the value earned.

Forecasting

EVM is not just about looking backward; its true power lies in forecasting the final project outcomes based on current trends.

Estimate at Completion (EAC)

The expected total cost of completing all work. There are several ways to calculate EAC depending on assumptions about future performance. The most common formula assumes that the project's current cost performance (CPI) will continue for the remainder of the project.

EAC = Budget at Completion (BAC) / CPI (Where BAC is the original total baseline budget.)

Estimate to Complete (ETC)

The expected cost to finish all the remaining project work.

ETC = EAC - AC

Variance at Completion (VAC)

The projected budget surplus or deficit at the end of the project.

VAC = BAC - EAC

• A negative VAC indicates a projected budget overrun.

EVM Example Scenario

A project to install streetlights has a total budget (BAC) of $500,000. By month 3, the plan called for completing $150,000 worth of work (PV = $150,000). An assessment shows that only $120,000 worth of work has actually been accomplished (EV = $120,000). The accounting system shows that $140,000 has been spent so far (AC = $140,000).

Analysis:

• SV = $120,000 (EV) - $150,000 (PV) = -$30,000. The project is behind schedule.
• SPI = $120,000 / $150,000 = 0.80. The project is only working at 80% of the planned schedule efficiency.
• CV = $120,000 (EV) - $140,000 (AC) = -$20,000. The project is over budget.
• CPI = $120,000 / $140,000 = 0.857. The project is getting about 86 cents of value for every dollar spent.
• EAC = $500,000 (BAC) / 0.857 (CPI) = $583,430. If current trends continue, the project will cost $583,430 at completion, resulting in an $83,430 overrun.