Just a thought after a recent matrix encounter. The teams hacker successfully took down 4 low end technomancers. His AE option on his attack program gives great advantage when outnumbered. It got me thinking about crashing programs and OS's. If for arguments sake 4 opponents all individually attempted to crash the same program (NOT as a teamwork test). Would there success's stack for purposes of success or not?

No, if they are not making a Teamwork test then I would say that each one would need to make an individual crash test on the program.

Guess I was looking at from a fluff angle, a build up of bugs would seem to eventually weigh down the program or OS. It boils down to are all crash attempts the exact same action or combination of different methods. But wanted some input before decided one way or the other.

I would rule seperate tests because I figure at least some of them are trying the same "basic" tricks.

I would make the same ruling for the reverse reason: they're not coordinating their attacks (that would be a teamwork test), so they're likely to approach the problem from different angles, which means the system's full stability measures apply to each attempt. If they were working together to, say, cause a buffer overflow, then the system would be easily overrun. If they try to overflow different buffers, the success of one is unlikely to affect another's attempt (as he won't know the other buffer is overflowed until it's too late to take advantage of it).