Can I cover a complete usecase with multiple apps?

My Client-Server application set-up is single-boxed where all the applications reside on the same machine.

There are numerous windows services, .NET apps, that interact with each other when I perform any use case on the machine. My question is, Can I measure coverage of all the applications for that use case while performing it.

It is not possible to profile these processes individually because the the number of times the use cases need to run will actually be 25-30 times my original effort. That means I will never be able to measure the complete coverage within the project life-time :)

I have tried running two instances of NCover launching two different processes at the same time and measure coverage while performing the use-case, however it increased my execution effort at least 4 times [1.5 to 2 times is my threshold].

Is there something I'm missing here? Can I use NCover API's, if any for this task?

RE: Can I cover a complete usecase with multiple apps?

You need to run NCover on all of the applications like you were doing. How has your effort increased by 4x?

No api's exist since NCover needs to hook into the process while it is starting up.

Joe