การออกแบบแผนการสุ่มตัวอย่างแบบต่อเนื่องประเภทที่ 1 ในการทดสอบคุณภาพทางไฟฟ้าสำหรับหัวอ่าน HSA เพื่อให้ได้ต้นทุนคุณภาพต่ำสุด / เสริมสุข แซ่ตั้ง = Design of continuous sampling plan 1 for HSA quasi static testing with the minimum cost of quality / Sermsuk Saetung
The objective of this research is to design continuous sampling plan 1 or CSP-1 for Quasi Static Testing of HSA (Head Stack Assembly) to replace 100% inspection in order to minimize cost of quality and prepare readiness to support demand increase in the future. This research began with literature review of theoretical background of CSP-1 sampling plan and cost of quality calculation. Previous research of CSP-1 sampling plans rarely considered economic value and if there were, only some elements of quality costs were considered. However, there were other costs incurred as a result of conducting the sampling plan but these costs were not included in the previous cost models. In this research, a modification of the previous cost models by additional concerned costs was deployed to find the most optimal parameters ( ). The quality costs involved in the modified cost model are categorized into three types. 1. Prevention costs: training cost, quality planning cost, and inspection equipment maintenance cost. 2. Appraisal costs: materials inspection cost and product quality audit cost. 3. Failure costs: rework cost, troubleshooting cost, scrap cost, and defective acceptance cost. Moreover, the equations of each of the cost elements were presented. As a result, with specific AOQL = 0.01, the optimal combination of parameters for this case study is i=130, ƒ=0.07. This designed sampling plan results in the cost of quality per unit of 11.16 baht, which is lower than that of 100% inspection for 4.05 baht or 26.6%.
