A vendor builds multiple types of tablet computers. Each has a type identification number and a name. The key specifications for each type include amount of storage space and display type. The company uses multiple processor types, exactly one of which is used for a specific tablet computer type; obviously, the same processor can be used in multiple types of tablets. Each processor has a manufacturer and a manufacturer's unique code that identifies it. i. Each individual tablet computer manufactured by the vendor (see 2h) is identified by the type identification number and a serial number that is unique within the type identification. The vendor wants to maintain information about when each tablet is shipped to a customer. j. Each of the tablet computer types (see 2h) has a specific operating system. Each technician the company employs is certified to assemble a specific tablet type—operating system combination. The validity of a certification starts on the day the employee passes a certification examination for the combination, and the certification is valid for a specific period of time that varies depending on tablet type—operating system combination