Rationale: Its very common for a interviewer to put some open-ended questions and observe the interviewee’s thought process.
Sample answer from a professional point of view
MEASURING TEST COVERAGE
- In terms of a feature; Test the tap function while serving the soda, Measure the iciness of soda, measure the size of a soda container while filling and then measure the size of soda while getting from tap
- In terms of part; iciness module, cooling engine, soda tapped functions, tank functions.
- Test the coolness of soda machine on certain weather condition,
- Test the freshness of soda while serving to customer on different-2 conditions,
- Test the taste of soda by preserving soda n number of days on different temperature,
- Test the soda machine on certain simulated environment
WHEN TO TEST
- Test while manufacturing the soda machine, e.g. test the solidness of a cabinet, test the leakage of the tank.
- Test on time to time on different-2 phases of manufacturing of soda machine
- Test the usability of machine
- Test the machine after assembly
If you please let me know some specific/exact information about soda machine then the above approach can be made specific.