Our parts warranty alert looks at 4 conditions - Days, Core Returnable, Clicks and does the cost exceed the vendor cutoff. More here. Once you get it set up and running and realize the dollars involved most clients want to maximize the process.
Our suggested best practice is to have the alert sent to your parts person and to require the technicians to return all parts. Our clients have experimented with having the alert go to the technician but found many cases where the tech said "didn't get the message until I had left the office". They have also found that saying "if it costs less than $X" also lead to confusion. Simple process is the tech keeps a box in the car, puts all used parts in there and return it to the shop periodically. The parts person has the list of parts they are looking for when they search that box.
Some manufacturers like Kyocera Mita will require a print out from the equipment, for this we suggest that only should you check the To Technician box but also have eAgent set up to auto invoice zero dollar calls and have that agent set to run every 15 minutes. Some clients will take an extra step to credit the part back to the call if the warranty is approved to correctly reflect contract profit and tech parts usage. See here for that discussion.