Department of Veterans Benefits Manual

DEPARTMENT OF VETERANS BENEFITS MANUAL

QUALITY CONTROL

WASHINGTON, D.C. 20420 AUGUST 22, 1966

M20-2 Department of Veterans Benefits

Veterans Administration

Washington, D.C. 204

August 22, 1966

Department of Veterans Benefits Manual M20-2, "Quality Control," is published for compliance by all concerned.

When applicable, the instructions and procedures in this manual will be referenced in other department administrative issues containing program quality control and evaluation instructions.

A.W. .STRATTON

Chief Benefits Director

Distribution: RPC 2124 assigned

FD

August 22, 1966 M20-2

INTRODUCTION

This is a working manual. It provides basic department instructions and procedures to be used in the development and maintenance of program and field station quality control activities. It includes basic sampling procedures which must be followed whenever samples are used to estimate a quality level, make quality comparisons, or to determine compliance with standards.

Quality control has assumed various forms in the past, but has always had quality improvement as the primary objective. The Department of Veterans Benefits previously introduced the use of statistical quality control techniques, because it would provide, at minimum cost, the information needed for quality improvement. Most quality control actions and related decisions are based largely on information obtained from samples. The cost of continuous 100 percent inspection of all work done would be prohibitive. Sampling has the obvious advantage of economy and speed. Since making inferences from samples is a basic function of statistics, in this sense every quality control plan involving sampling is statistical quality control.

This manual explains statistical quality control techniques in sufficient detail for careful observance of sound sampling procedures and other basic statistical principles. Just enough theory is included to provide working rules for the application of the more commonly used techniques and for recognizing also the limitations of such techniques. It presents the management point of view toward quality control as well as basic operating rules. In addition, this manual may be used in the following ways:

1.As a guide for improving program and field station quality control methods.

2.As a reference for operating personnel in conducting quality control activities.

3.As a guide for estimating and evaluating quality levels to identify improvement needs.

4.As a text for use in conducting supervisory training sessions in quality control.

M20-2August 22, 1966
RESCISSIONS

1. Interim Issue
/Section V and appendix A, EM 28-2

2.DVB Circular

20-64-17

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August 22, 1966 M20-2

CONTENTS

PARAGRAPH PAGE

CHAPTER 1. GENERAL QUALITY CONTROL INSTRUCTIONS

1.01Quality ------1-1

1.02Quality, Control ------1-1

1.03Objectives of Quality Control in DVB ------1-1

1.04Byproducts of Effective Quality Control ------1-1

1.05Quality Control Methods ------1-2

1.06Responsibilities ------1-2

1.07Organizing for Quality Control ------1-3

1.08Quality Control Principles ------1-4

1.09Error or Quality Defect ------1-5

1.10Sampling Procedures ------1-5

1.11Feedback--Key to Quality Planning and Control ------1-7

1.12Timeliness of Operations ------1-7

1.13Complaints--Significant Quality Indicator ------1-7

CHAPTER 2. STATISTICAL QUALITY CONTROL

2.01SQC Applications ------2-1

2.02Quality Mindedness ------2-1

2.03Functions of SQC ------2-1

2.04Cost of Quality--SQC ------2-1

2.05Developing an SQC Plan ------2-2

2.06SQC Measurements and Standards ------2-3

2.07Timeliness Measures and Standards ------2-3

2.08Quality Level ------2-4

2.09Revising Acceptable Quality Level or Standard ------2-4

CHAPTER 3. SAMPLING VARIATION IN QUALITY CONTROL

3.01 Recognition of Sampling Variation ------3-1

3.02 Error Distribution--Small Finite Population ------3-1

3.03Characteristics of Sample Combinations ------3-1

3.04Frequency of Occurrence of Possible Sample Combinations - - -3-2

3.05Variability in a Random Sample Result ------3-2

3.06 Applying Principles of Statistical Sampling to Quality Control ------3-3

CHAPTER 4. TABLE OF THREE STANDARD DEVIATION CONTROL

LIMITS FOR PERCENT IN ERROR

4.01 Purpose of the Table ------4-1

4.02 Control Limits Used in the Table ------4-1

4.03 What the Table Shows ------4-1

4.04Assumptions in Using the Table to Interpret Sample Results - - - - -4-2

4.05Determining Whether a Process is in Statistical Control ------4-2

4.06Determining Sampling Error ------4-3

4.07Determining Sample Size ------4-4

4.08How to Use the Table When Quality Level (Percent in Error)

Exceeds 500% ------4-5

4.09Use of Independent Samples and Table to Verify Reported Quality

Levels ------4-5

4.10Review of Cases or Work Units Previously Quality Checked by the

Supervisor ------4-7

4.11 Determining Compliance With Standards of Timeliness ------4-7

4.12Mathematical Formulas Used to Develop the Table of Three Standard

Deviation Control Limits ------4-10

M20-2 August 22, 1966

CONTENTS--Continued

PARAGRAPH PAGE

CHAPTER 5. SQC CHART FOR PERCENT IN ERROR

5.01 Management Value of SQC Charts ------5-1

5.02SQC Chart Influence on Quality Improvement ------5-1

5.03SQC Chart Design ------5-1

5.04Control Chart Evidence ------5-2

5.05SQC Chart Evidence of a Quality Level Better Than the Standard - 5-6

5.06Tendency to Ignore Favorable SQC Chart Evidence ------5-7

APPENDIXES

APPENDIX

AGlossary of Terms - -App. A-1
BSQC Chart Illustration App. B- I
CTable of Random Sampling NumbersApp. C-1
DMinimum Acceptable Sample Percentages for Specified Percentages

of Work Units Processed ------App. D- I
ETable of Three Standard Deviation Control Limits for Percent in Error App. E- I

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