Duke has been in private practice since 1985 working with manufacturing and healthcare industries as well as financial and government services. He has conducted hundreds of workshops on ISO 9001 and quality audits, failure mode & effects analysis and risk-based thinking, and performance metrics and root cause analysis. He is author of three books on quality management topics: Root Cause Analysis: The Core of Problem Solving and Corrective Action (2nd ed.), Performance Metrics: The Levers for Process Management, and Musings on Internal Quality Audits: Having a Greater Impact. He holds degrees in technology, business and education, and is an ASQ Fellow and certified as a CMQ/OE, CQE and CQA.