To provide better detail, our company has bid our product for a potential government contract. Their response has requested a MTBF of the system. I have the following questions?

1. If our product is a protoype, can a MTBF been performed?

2. Without official tests can MTBF be calculated?

3. If I have the MTBF data from our suppliers for subcomponents, what is the easiest way to calculate and combine these values to represent the system?

I can do the simple math of MTBF, but how can I compile these to reflect a system MTBF?

Thanks!