OQA and ORT of QA have detected the problem before ship product to customer found SUS3xx and SUS4xx contamination defect are the Top fifth of highlight problem for Capacity Enterprise product then APK is major product of them that the first major highlight . there are Baseline around 14 DPPM that against the Target 5 DPPM that may be concerned to the quality of HDD of company and customer so we pick up this problem to improve .