Once your WBS is established, you can apply Earned Value Management (EVM) to manage and measure project performance.
In the capstone, "cost" is based on the hours you plan to spend, not money.
Budget at Completion (BAC) = Total planned project hours.
(Sum of the BCWS for all WBS elements.)
This is static throughout the project and should not change unless the scope of your project changes.
BCWS (Budgeted Cost of Work Scheduled) = How much work you planned to have completed by now.
(Planned hours for the deliverable by the current report's date.)
BCWP (Budgeted Cost of Work Performed) = How much work you actually completed so far.
(Planned hours for the work actually finished by the current report's date.)
ACWP (Actual Cost of Work Performed) = How many hours you actually spent working on the deliverable.
Example (Using Requirements Analysis Report - RAR):
The Requirements Report is estimated to take 30 labor hours total.
Your schedule says you should have finished it this week.
✅ If you actually finished it:
BCWS = 30 hours (planned to be done)
BCWP = 30 hours (done)
ACWP = 28 hours (you only spent 28 hours doing it)
🛑 If you're only halfway done:
BCWS = 30 hours (planned to be done)
BCWP = 15 hours (only half is done, so only half is earned)
ACWP = 20 hours (you spent 20 hours working so far just to get half way done)
SPI (Schedule Performance Index) = BCWP ÷ BCWS
(Are you ahead or behind schedule?)
SPI > 1 means you're ahead of schedule.
SPI < 1 means you're behind schedule.
SPI should always = 1 at the end of the project since all of your work has been completed.
CPI (Cost Performance Index) = BCWP ÷ ACWP
(Are you spending more or less time than expected?)
CPI > 1 means you are spending fewer hours than planned to accomplish the work.
CPI < 1 means you are spending more hours than planned to accomplish the work.
EAC (Estimate at Completion) = BAC ÷ CPI
(Your latest projection of total project hours based on current performance.)
Example: Estimate at Completion (EAC)
Let's say:
BAC = 260 hours (total planned project effort)
BCWP = 130 hours (you have earned 130 hours of work so far)
ACWP = 160 hours (you have actually spent 160 hours so far)
First, calculate CPI:
CPI = BCWP / ACWP = 130 / 160 = 0.8125
Now, estimate EAC:
EAC = BAC / CPI
EAC = 260 / 0.8125
EAC ≈ 320 hours
Interpretation: At your current efficiency, you are projected to need about 320 hours to complete the project — about 60 hours more than originally planned.
TCPI (To-Complete Performance Index) (Optional)
Formula:
TCPI = (BAC - BCWP) ÷ (BAC - ACWP)
Purpose:
TCPI shows the efficiency you need to achieve for the rest of the project to finish on time and within your original planned budget.
TCPI > 1 → You will need to perform better than you have been so far to stay on budget.
TCPI < 1 → You can maintain your current pace or even slightly lower efficiency and still finish on budget
You can calculate TCPI at any point for a quick reality check on how much you need to "tighten up" (or not) during the second half of your project.
Example:
BAC = 260 hours
BCWP = 130 hours (earned value so far)
ACWP = 160 hours (actual hours spent so far)
First, calculate TCPI:
TCPI = (260 - 130) ÷ (260 - 160)
TCPI = 130 ÷ 100
TCPI = 1.3
Interpretation:
You will need to be 30% more efficient than you have been so far in order to finish the project within your original 260-hour plan.
Deliverable:
You should update and track BCWS, BCWP, ACWP, SPI, CPI, EAC (and optionally TCPI) throughout the semester as you complete major deliverables.
You should include trend charts showing your SPI and CPI over time in each of your derliverables.
For your capstone project, you should track EVM progress using percent complete updates weekly.
Every week, you should estimate what percentage of each active task has been completed and update your BCWP (earned value) accordingly.
Why use weekly percent complete updates?
It gives a more realistic and continuous view of your project progress.
Problems or delays can be detected early — and early correction is always easier than late correction.
In the real world, Systems Engineers and project managers are expected to monitor progress regularly, not just at major milestones.
Why not use 0/100 or 50/50 rules?
0/100 Rule: You earn 0% until the task is fully complete. This hides schedule slips until it's too late to react. It gives no visibility into partial progress.
50/50 Rule: You earn 50% when you start and 50% when you finish. This can badly distort reality if you start many tasks but finish few. It overstates progress early and gives no insight into how close you really are to completion.
For the capstone, you need better resolution than either of these can provide.