How would you test a vending machines? Write some test cases.
Sigiloso
I would apply functional testing : trying all documented functionality at first; then I would apply Ad-Hoc testing: "shake" pressing on all buttons all together.. trying to crack it all the way... plug-in and out electricity etc. Integration testing (software / hardware) white and black box testing (program and interface) boundary testing, security testing, etc. Anything can be tested in many ways but the best way to find a glitch or bug.. is to think out of box and use Ad-Hoc... even though it is hard to document bugs that was found using such method, better to know that such bugs exists before lunching the product! :)