Guidelines for Laboratory Quality Managers

This useful and extensive set of guidelines is designed to assist food control laboratories in gaining accreditation from an internationally recognized external body, providing all of the necessary information and practices in an easy-to-read, step-by-step fashion. Authored by an experienced consultant for laboratory accreditation in many different countries, with this text food control lab owners now have all of the up-to-date information they need to gain accreditation in a single source. Guidelines for Laboratory Quality Managers covers the essentials for quality management in the food control laboratory, from testing processes to current quality management systems. The ISO standards for accreditation are extensively explored, including managerial requirements, organizational aspects, complaint handling procedures, internal audits, and sampling. An entire section is dedicated to the implementation of managerial and technical requirements from quality control to program monitoring and evaluation. Analysis selection, preparation, and validation is covered extensively, and an entire section is dedicated to basic statistics from data presentation to distribution. Each section comes with helpful tips for lab managers plus definitions and terms. Comprehensive, easy-to-use and up-to-date, Guidelines for Laboratory Quality Managers is the guide for accreditation for food control laboratories. Preface 7 Acknowledgments 8 Contents 9 Chapter 1: Introduction and ISO17025:2017 14 1.1 Clause 1: Scope 15 1.2 Clause 2: Normative References 15 1.3 Clause 3: Terms and Definitions 15 1.4 Clause 4: General Requirements 15 1.4.1 Impartiality 16 1.4.2 Confidentiality 16 1.5 Clause 5.0: Structural Requirements 16 1.6 Clause 6.0: Resources Requirements 16 1.6.1 General 16 1.6.2 Personnel 17 1.6.3 Facilities and Environmental Conditions 17 1.6.4 Equipment 17 1.6.5 Metrological Traceability 18 1.6.6 Externally Provided Products and Services 18 1.7 Clause 7.0: Process Requirements 19 1.7.1 Review of Requests, Tenders and Contracts 20 1.7.2 Selection, Verification, and Validation of the Methods 20 1.7.3 Sampling 20 1.7.4 Handling of Test or Calibration Items 21 1.7.5 Technical Records 21 1.7.6 Evaluation of Measurements Uncertainty 21 1.7.7 Ensuring the Validity of Results 21 1.7.8 Reporting Results 22 1.7.9 Complaints 22 1.7.10 Nonconforming Work 23 1.7.11 Control of Data – Information Management 23 1.8 Clause 8.0: Management System Requirements 24 1.8.1 Management System Documentation (Option A) 24 1.8.2 Control of Management System Documents (Option A) 25 1.8.3 Control of Records (Option A) 26 1.8.4 Actions to Address Risks and Opportunities (Option A) 27 1.8.5 Improvement (Option A) 27 1.8.6 Corrective Actions (Option A) 27 1.8.7 Internal Audits (Option A) 28 1.8.8 Management Reviews (Option A) 28 Chapter 2: Essentials for Quality Management in a Chemical Testing Laboratory 30 2.1 Managing the Quality of Laboratory Testing Processes 30 2.2 Developing a Quality Management System (QMS) 31 2.2.1 PLAN 31 2.2.2 DO 32 2.2.3 CHECK 32 2.2.4 ACT 32 2.3 Six Sigma Quality Management System 33 2.3.1 Define, Measure, Analyze, Improve Stages 34 2.3.1.1 Define Stage 34 2.3.1.2 Measure Stage 34 2.3.1.3 Analyze Stage 35 2.3.1.4 Improve Stage 35 2.4 Quality Systems 36 2.4.1 Quality System, Assurance, Assessment and Control 36 2.4.2 Principles of Quality Control 37 2.4.3 Principles of Quality Assessment 37 2.4.4 System Planning 38 2.4.5 Investigation Phase 38 2.4.6 Quality Manager Responsibilities 39 2.4.7 Steering Team Responsibilities 40 2.4.8 Task Team Responsibility 40 2.4.9 Timeline 41 2.4.10 Implementation Phase 41 2.4.11 Consolidating the Program 42 2.4.12 Monitoring and Evaluating the Program 43 2.4.13 Management Review 43 2.4.14 Communication and Motivation 44 2.5 Tips 44 2.5.1 Tip: 1 – Human Resources 44 2.5.2 Tip: 2 – Scheduling and Conducting the Gap Analysis 45 2.5.3 Tip: 3 – Quality Manual 47 2.5.4 Tip: 4 – Example of Task Assignments 47 2.5.5 Tip: 5 – Example of Project Gantt Chart 48 Chapter 3: Preparing for Analysis: The Analytical Method 49 3.1 Sources of Methods 49 3.2 Evaluation of Published Methods 51 3.3 AOAC International (AOACI) 51 3.4 The Codex Alimentarius Commission 52 3.5 The European Union 52 3.6 The European Committee for Standardization (CEN) 53 3.7 ISO 54 Chapter 4: Statistics for the Quality Control Laboratory 56 4.1 Data Presentation 57 4.2 Measure of the Central Tendency (Mean, Median, Mode) 57 4.2.1 Median 57 4.2.2 Mode 58 4.3 Measures of Spread (Range, Variance, Standard Deviation) 58 4.3.1 Range 58 4.3.2 Variance 58 4.3.3 Standard Deviation 59 4.4 Normal Distribution 60 4.5 Using Samples to Estimate Population Values 61 4.6 Standard Error of the Mean 62 4.7 Shapiro-Wilks for Testing Normality 63 4.7.1 Sulphur Dioxide SO2 in White Wine 64 4.8 Confidence Intervals 65 4.9 Steps in the Process of Hypothesis Testing 66 4.10 Example of Statistical Tests Routinely Applied in the Analytical Laboratory 68 4.11 F-Test 68 4.11.1 Comparison of Two Standard Deviations: The F-Test 68 4.12 Outliers 70 4.12.1 Outliers-Dixon Test 70 4.12.2 Grubbs Test 71 4.13 Cochran Test for Extreme Value of Variance (Outlier Variance) 72 4.14 Combining (Pooling) Estimates of Standard Deviations 73 4.15 Precision Calculations 73 4.16 Averages 76 4.16.1 Comparison of Means: The T-Test 76 4.17 Comparing Two Averages by Using the T-Test 78 4.18 The Repeatability Limit (r) 81 4.19 The Calibration Process: Regression Line 83 4.20 Weighted Regression Line 86 4.20.1 TIP 87 4.20.1.1 The Correlation Coefficient 87 4.21 Method of Standard Addition (MOSA) 87 4.22 Errors, Linear Regression Analysis and Method of Standard Additions 89 4.22.1 Some Definitions 89 4.22.2 Errors in Chemical Analysis 90 4.22.3 Constant Error 90 4.22.4 Proportional Errors 90 4.23 The Youden Approach to Constant and Proportional Errors 91 4.24 ANOVA- Analysis of Variance 95 4.24.1 The ANOVA Summary Table: General Format 96 4.25 Two-Way ANOVA 100 4.25.1 The Two-Way ANOVA Summary Table 101 4.26 Meaning of p-Value 104 Appendix 104 Shapiro-Wilk Test 104 Grubb Statistic Values 106 Chapter 5: Uncertainty Measurements 110 5.1 Approaches to Estimate Measurement Uncertainty 111 5.1.1 The Bottom Up Approach 112 5.1.1.1 How to Calculate the Standard Uncertainty for a Type A Evaluation 113 5.1.1.2 How to Calculate the Standard Uncertainty for a Type B Evaluation 113 5.1.2 Top Down Approach 115 5.1.2.1 Top-Down’ Requirements 116 5.2 Case Study – Determination of Cholesterol in Animal and Vegetable Fats and Oils 116 5.3 Example 2 119 5.3.1 Estimation of Measurement Uncertainty 119 5.3.2 Estimation of Bias and the Uncertainty of Bias 120 5.3.3 Result Corrected for Bias 120 5.3.4 Result Not Corrected for Bias 121 5.4 Other Approaches to Estimate MU: The Horwitz Equation 121 5.5 HORRAT Value 123 Chapter 6: Control Charts and Process Capability 127 6.1 Control Charts 127 6.2 Construction of a Control Chart 128 6.3 Type of Control Charts: Average, Range and Standard Deviation Control Charts 129 6.4 Quality Control Samples 134 6.5 Guidelines on Interpretation of Control Charts 135 6.6 Practical Points in Using a Control Chart 136 6.7 Process Capability 137 6.8 Capability Indices Cp and Cpk 139 6.9 How to Conduct a Functionality Study 141 6.10 Process Capability Analysis: An Example 142 6.11 Six Sigma and Process Capability 143 6.12 Process Capability Index Cpk and Six-Sigma Metric 146 6.13 Conclusions 148 Chapter 7: Risk Management 149 7.1 Risk Management Requirements in the New Laboratory Standard ISO17025 149 7.2 Addressing Risks 150 7.3 Addressing Opportunities 150 7.4 Integrating and Implementing Actions 150 7.5 Risk Management 151 7.6 Risk Identification 152 7.7 Failure Modes and Effects Analysis (FMEA) for Laboratory 154 7.8 Probability of Occurrence 155 7.9 Probability of Occurrence with Standard Linear Scaling 155 7.10 Severity 156 7.11 Risk Mitigation 157 7.11.1 Table Form for Risk Mitigation 158 7.12 Detection Level 158 7.12.1 Detection Level Table 158 7.13 RPN Calculation 159 7.14 Examples 159 7.14.1 Medical Example: Prostate Specific Antigen (PSA) Test 160 7.14.2 Example 2: HUMIDITY for Rice and Mill Analysis 161 7.15 Sampling Frequency 162 7.15.1 Quantitative Overall Risk Assessment (Simplified) 162 7.16 Frequency of Sampling/Analysis 162 7.16.1 Quantitative Risk Assessment (Simplified) Incorporating Example Exponential Weighting Function (Notional) 163 7.17 Useful Reading 163 7.18 Example of Risk Assessment for an Analytical Method from sampling Collection to Test Results 164 Index 169