SR NWT 000821 : ISSUE 3

1 INTRODUCTION
1.1 Document Organization
1.2 Changes
2 PURPOSE AND SCOPE
2.1 Quantifiable Characteristics
2.2 Qualitative Characteristics
3 WHAT PRODUCTS SHOULD BE STUDIED?
4 STUDY POPULATION
4.1 Minimum Number of Units
4.2 Centralized Population
4.3 Representative Sample
4.4 New Versus Repaired Units
5 TYPES OF FIELD RELIABILITY PERFORMANCE STUDY
6 DETAILED FIELD RELIABILITY PERFORMANCE STUDY
6.1 Guidelines for Considering the Detailed Approach
6.2 Planning a Detailed Field Performance Study
6.3 Considerations in Tracking Procedures
6.4 Determining the Sample Size
6.5 Preparing the Study Materials
6.6 Software Support Tools
6.7 Field Performance Study Team
6.8 Summary of Steps in Conducting the Study
7 PICS/DCPR REPORTS
7.1 Reports to be Used
7.2 Inventory Data
7.3 Removal Data
7.4 Removal Rates
7.5 Failure Rates
8 SERIALIZED BAR CODE
8.1 Basic Steps
8.2 Future Development
9 SAMPLE SIZE GUIDELINES
9.1 Introduction
9.2 Percentage Defective Cases
9.3 Failure Rate Cases
9.4 Summary of Sources
10 DATA ANALYSIS AND REPORTS
10.1 Introduction
10.2 Estimating Initially Defective Percentages -
                  One Sample
10.3 Estimating Initially Defective Percentages -
                  Two Samples
10.4 Estimating Steady-State Failure Rates
10.5 Comparing Two Steady-State Failure Rates
10.6 Estimating Early-Life Failure Rates
10.7 Summary of Sources
10.8 Replacement Rates
10.9 Reporting of Replacement/Failure Rates
11 COMPLIANCE AND MISSING DATA
12 SURVEY
13 ANALYSIS OF SOFTWARE PERFORMANCE DATA
13.1 Software Fault Data
13.2 Software Data Analysis
14 RELIABILITY AND QUALITY MEASUREMENTS REPORTS
14.1 Determination of Study Population and Period
14.2 List of RQMS Report Measurements
14.3 Useful Measurements in Field Performance Studies
14.4 Input Format and Report Examples
Data Input Format
Data Input Format
15 FOLLOWUP FOR CORRECTIVE ACTION
15.1 General
15.2 Product Performance Meetings
15.3 Action Item Register
15.4 Reliability Review Forums
16 GLOSSARY
16.1 Definitions
16.2 Acronyms
17 REFERENCES
Appendix A A Flow Chart of Movements of Removed Units
Appendix B Minimum Sample Size for One Proportion
Appendix C Minimum Sample Size for Comparing Two Proportions
Appendix D Factors for the Sample Size and Confidence
                  Interval Computations
Appendix E Threshold of Significance (FA,B) for Comparing
                  Two Failure Rates
Appendix F An Example of a Survey of Supplier Documentation
                  and Product Support
Appendix G An Example of a Survey of Training
Appendix H An Example of an Action Item Register
LIST OF FIGURES
Figure 6-1 Serialized Study Labels
Figure 6-2 Inventory Form
Figure 6-3 Sample Study Event Ticket
Figure 6-4 A Study Log
Figure 10-1 Observed and Predicted Replacement Rates
                  (%/Year) for a Circuit Pack Code
Figure 14-1 Example of Downtime Performance Measurements
Figure 14-2 Example of Defective Patch Measurement
Figure 14-3 Example of Circuit Pack Return and NTF
                  Measurements
Figure 14-4 Example of PR Measurements
Figure 14-5 Example of Fault/Fix History Measurements
LIST OF TABLES
Table 7-1 Inventory File Report
Table 7-2 ECI Transaction File Report
Table 7-3 Historical Movement Report
Table 9-1 Four Cases Considered
Table 9-2 Sources Used for Sample Size Determination
Table 10-1 Sources Used for Confidence Limits
                  Determination
Table 10-2 Observed and Predicted Replacement Rates
                  (RITS) for a Circuit Pack Code
Table 14-1 RQMS Report Measurements

Provides Bellcore's view of generic guidelines for conducting Field Reliability Performance Studies (FRPSs). The handbook is primarily intended for use by Bell Client Companies (BCCs) who wish to run their own studies. However, the principles, as described, are applicable to any FRPS administered by Bellcore or suppliers of telecommunications equipment for assessing the in-service performance of products/systems.