Explain why it is difficult to validate a reusable component without the component source code. In what ways would a formal component specification simplify the problems of validation?

What will be an ideal response?

Component validation without source code is very difficult because there is no way
of assessing how the component handles exceptions (and this is rarely defined in a
component specification). The only validation method that can be used is black-box
testing so static techniques cannot be used. Component specifications are rarely
complete and this increases the problems of black-box testing. Formal
specifications would help because they would precisely define what the component
was supposed to do and its actual behaviour could be compared to the specification.
However, formal specification rarely cover all exceptions and they do not help with
testing performance, dependability or other non-functional characteristics.