There are several advantages to using EVM. Of course, you must keep it scalable. Government agencies working on billion dollar multi-year projects hopefully have a full EVM implementation. I've used it on projects as small as $50K because it becomes a very easy way to explain to clients how the project is going and their money is being spent. I didn't have anything more than a spreadsheet and a once every week or two trip to the finance department (other side of the building) to manage with EVM.
The key advantages are:
- Able to combine cost and time into a single view. It should be difficult to run out of budget, but have more than 50% of the schedule left without knowing it.
- Able to deal with uneven rates of expenditures.
- Provides an early warning when corrective action is required.
- Provides accurate and trusted data (EVM makes project finances and schedule very transparent).