電子製造業通常採用抽樣檢驗作為其產品品質管制的方法，自美國國防部於1996年發行MIL-STD-1916 抽樣計畫取代MIL-STD-105E抽樣計畫。產業界面臨執行MIL-STD-1916 抽樣計畫時如何選擇驗證水準(VL)的問題，因其驗證水準並非如MIL-STD-105E抽樣計畫AQL為產品允收標準的明確指標。本研究在實例中運用統計學理論超幾何分配計算在不同擇驗證水準下抽樣檢驗成本、預期檢驗風險損失與客戶退貨風險損失。結果顯示MIL-STD-1916 計數值抽樣計畫下不同驗證水準對生產者利潤所造成的影響。

Sampling inspection is the quality control measure often used in the electronic manufacturing industry. Since the U.S. Department of Defense issued MIL-STD-1916 sampling plan to replace MIL-STD-105E in 1996, the industry has faced a problem as VL is not as a clear index of acceptance standard as AQL of MIL-STD-105E. This research employs hypergeometric distribution of statistical theory to calculate the cost of sampling inspection and potential profit loss of a lot as a result of expected inspection and that of return shipment from customer with different VLs in real case of company A. The result shows the effect at different VLs under MIL-STD-1916 sampling plan.

TABLE OF CONTENTS
Chapter 1 Instruction.................................................... 1
1.1 Background........................................................... 1
1.2 Motivation and Purpose...............................................2
1.3 Overview of the study................................................2

Chapter 2 Literature Review..............................................4
2.1 Current status of sampling inspection in the electronic industry..... 4
2.2 MIL-STD-1916 sampling inspection literature review................... 5
2.3 MIL-STD-105E and MIL-STD-1916 Comparison............................. 7
2.4 Terminology of sampling inspection................................... 8

Chapter 3 Research Design............................................10
3.1 MIL-STD-1916 attribute sampling plan introduction.................... 10
3.2 Hypergeometric distribution................................12
3.3 The content and precondition of research............................. 13
3.3.1 Acceptance standard and the hypothesis of defective rates.......... 13
3.3.2 The probability of qualification................................... 15
3.3.3 The probability of rejection by customers.......................... 15
3.3.4 The risk of sampling inspection.................................... 17
3.4 Operating Characteristics Curve of MIL-STD-1916 sampling plan........ 17
3.5 Sample inspection process..............................18
3.5.1 Unit pass or loss during sampling inspection under MIL-STD-1916....18
3.5.2 Expected inspection value.......................................... 20
3.5.3 The loss of risk from customer’s rejection........................ 21

Chapter 4 Case Study........................................ 22
4.1 Background of the case study company................................. 22
4.2 The analysis of case.................................. 23
4.2.1 The cost of sampling inspection.................................... 23
4.2.2 The cost involved in expected inspection to manufacturer EC (n,x).. 26
4.2.3 The sum of profit from risk evaluation............... 30
4.3 Potential profit loss of expected inspection and rejection by customer between MIL-STD-1916 and MIL-STD-105E..........................31
4.4 Potential Profit loss of expected inspection versus rejection by customer in real-life situations.....................36
4.4.1 Revised potential Profit loss of expected inspection and rejection by customer......................................36
4.4.2 Revised sum profit of risk evaluation..............................40
4.5 Calculation of lost order impact.....................................42

CHAPTER 5 Conclusions.............................................44
Reference.............................................46
Appendix: The conversion rules of MIL-STD-11916 sampling plan.........47

LIST OF FIGHRES
Figure 1: The probability of MIL-STD-1916 sampling plan with 1 defective unit.......................................16
Figure 2: The probability of MIL-STD-1916 sampling plan with 10 defective units........................16
Figure 3: The perfect OC curve........................................17
Figure 4: OC curve of MIL-STD-1916 attribute sampling plan.........18
Figure 5A: Sampling inspection process............................19
Figure 5B: Manufacturers’loss calculation.......................19
Figure 6: Gross profit per product.............................25
Figure 7: Potential profit loss of expected inspection...................27
Figure 8: Potential profit loss of rejection by customer.................29
Figure 9: The sum of profit with risk evaluation.........................31
Figure 10: The comparison of potential profit loss of expected inspection between MIL-STD-1916 and MIL-STD-105E..................34
Figure 11: The comparison of potential profit loss of rejection between MIL-STD-1916 and MIL-STD-105E.....................34
Figure 12: The comparison of the sum of profit between MIL-STD-1916 and MIL-STD-105E.......................................36
Figure 13: Revised potential profit loss of expected inspection..........39
Figure 14: Revised potential profit loss of rejection by customer........40
Figure 15: Revised sum of profit with risk evaluation................41
Figure 16: The loss of orders from customers...............43

LIST OF TABLES
Table 1: Code letter of MIL-STD-1916 attribute sampling plan.............11
Table 2: The sample quantity of MIL-STD-1916 attribute sampling plan.....12
Table 3: The probability of sample disqualification, qualification and rejection................15
Table 4: The direct cost and various cost per product....................23
Table 5: Gross profit per product......................................25
Table 6: Potential profit loss of expected inspection....................27
Table 7: Potential profit loss of rejection by customer..................29
Table 8: The sum of profit with risk evaluation.......................30
Table 9: Acceptance guides by three levels under MIL-STD-105 normal inspection........32
Table 10: Potential profit loss of expected inspection and rejection by customer under MIL-STD-105E normal inspection level AQL0.65.........33
Table 11: The sum of profit under MIL-STD-105E normal inspection AQL 0.65......35
Table 12: Revised probability of disqualification, qualification, and rejection by customer .......................38
Table 13: Revised potential profit loss of expected inspection...........39
Table 14: Revised potential profit loss of rejection by customer.........40
Table 15: Revised sum of profit with risk evaluation..............41

1. MIL-STD-105E (1989), Military Standard: Sampling Procedures and Tables for Inspection by Attributes.
2. MIL-STD-1916 (1996), Department of Defense Test Method Standard: DOD Preferred Methods for Acceptance of Product
3. Montgomery, Douglas C. (2009), Introduction to Statistical Quality Control, 6th ed., John Wiley & Sons Inc, NJ.
4.Calvin(2008)，「漫談品質之風險管理」，品質月刊，第41卷，第10期，頁52-56。
5.王森信(2000)，「抽樣檢驗技術實施探討」，品質月刊，第36卷，第5期，頁58-60。
6.林智祥(2007) ，「MIL-STD-1916抽樣計劃表介紹 」，連展人2007 3月號，頁53-58
7.莊寶雕、李祥林和黃仕慶(2004)，「電子組裝業抽樣計畫與品質水準之探討」，第10 屆全國品質管理研討會論文集，A2-2，頁12∼22。
8.翁山田(2004)，「抽樣與檢驗」品質月刊，第40卷，第2期，頁59-63。
9.張有成(2002），抽樣檢驗，增訂版，中華民國品質學會。
10.張有成(2005)，「MIL-STD-1916與MIL-STD-105E應用之比較」，品質月刊，第41卷，第5期，頁86-90。
11.楊義明、盤天培和鄭鴻業(2005)，「MIL-STD-1916與105E之轉換」，品質月刊，第57卷，第10期，頁57-62。