The following costs were incurred by Osaka Metals Company to maintain the quality of its products. (Yen is the national currency of Japan.)
1. Operating an X-ray machine to detect faulty welds, 110,000 yen
2. Repairs of products sold last year, 116,000 yen
3. Cost of rewelding faulty joints, 17,000 yen
4. Cost of sending machine operators to a three-week training program so they could learn to use new production equipment with a lower defect rate, 18,100 yen
Required:
Classify each of these costs as a prevention, appraisal, internal failure, or external failure cost?