EVM is a series of practices that include work definition, planning (schedule and cost), work assignment, cost collection, discrete measurement of accomplishment and forecasting of cost and schedule at completion.

The reason for all of the detail in work definition is to make sure that the proper work can be assigned at the proper time to the responsible manager and to identify changes appropriately. If your project is not big enough to require tracking this, then that part may seem overly burdensome.

If you have standard practices in place that provide complete work definition and you can easily tell the responsible manager who can answer the question “why did that happen”, again EVM may seem burdensome.

If, on the other hand, your projects are not finishing on time or budget and you did not have any visibility into that end, I suggest you investigate EVM. EVM provides excellent visibility in to project progress against the baseline and forecast of completion cost and schedule information.

Like any other tool, it can be used well or poorly. It will not stop a project from being late or overrun. What it is designed to do is provide visibility soon enough, at a level of detail that allows root ccause analysis so that effective management decisions can be made in time to minimize negative impacts.

As to the size, here in the USA, the government requirements vary but generally any project of $20 million or larger will use EVM to manage and report to the cusotmer. Some agencies apply the requirement to projects as small as $2 million.