Quality, Warranty and Preventive Maintenance

Quality, Warranty and Preventive Maintenance examines the impact of product quality on warranty and maintenance costs and strategies, from the perspectives of both manufacturers and users. In addition, the theories of warranty and preventive maintenance are introduced and discussed. Common wisdom supports the notion that better product quality means lower warranty costs for the manufacturer, and lower maintenance costs for the users of a manufactured product. This proposition is examined in some detail on the basis of failure time models. The authors investigate what exactly better quality means in warranty and maintenance management, and how it impacts warranty policies and costs for the manufacturer, and replacement and maintenance strategies and costs for the users. In measuring quality improvement, the main concepts and tools used are those of stochastic ordering and mixture models. The theoretical base of the work is a time-varying failure-rectification process. This process includes, as special cases, replacement, minimal repair, and imperfect repair, as alternative rectification modes that may be available to the manufacturer or the user in warranty-servicing or maintaining a product. In addition to serving as a unifying base for the entire monograph, the use of this process enables one to investigate jointly optimal repair-effort/warranty-policy and repair-effort/maintenance-strategy configurations for repairable units. This book should be of interest to researchers in industry and academia, and to quality, warranty and maintenance professionals, specialists, and managers with a technical background. It is suitable as a textbook to support graduate-level seminar courses in OR/MS, IE and business administration curricula.

Contenu

1 Introduction.- 1.1 Warranty.- 1.1.1 Warranty Content.- 1.1.2 Warranty Duration.- 1.1.3 Warranty Type.- 1.1.4 Extended Warranties.- 1.1.5 Quality and Warranty.- 1.2 Preventive Maintenance.- 1.2.1 Rectification Modes.- 1.2.2 Rectification Period and Maintenance Cycle.- 1.2.3 Replacement Strategies.- 1.2.4 Quality and Preventive Maintenance.- 1.3 Objectives, Scope and Summary.- 1.3.1 Unit Warranties.- 1.3.2 Perpetual Warranties.- 1.3.3 Extended Warranties.- 1.3.4 Preventive Maintenance.- 1.4 Notation.- 2 Reliability and Quality Measures.- 2.1 The Failure Process.- 2.1.1 Integral Equation of the Process.- 2.1.2 Recurrence Times.- 2.1.3 Replacement on Failure.- 2.1.4 Minimal Repair.- 2.1.5 Imperfect Repair.- 2.2 Measuring Quality Improvement.- 2.2.1 Mean-and-Variance Ordering.- 2.2.2 Stochastic Ordering.- 2.2.3 Other Partial Ordering Relations.- 2.2.4 Mixture Models.- 2.2.5 Examples.- 3 Unit Warranties.- 3.1 Free-Rectification Warranties.- 3.1.1 Distribution of Warranty Cost.- 3.1.2 Optimal Rectification Effort.- 3.1.3 Impact of Quality.- 3.2 Pro-Rata Replacement Warranties.- 3.2.1 Variables of Interest.- 3.2.2 Examples.- 3.3 Combination Warranties and Warranty Policy.- 3.3.1 Probability Distributions.- 3.3.2 Warranty Policy Design.- 4 Perpetual Warranties.- 4.1 Long-Life-Cycle, Free-Rectification Warranties.- 4.1.1 Cost Rates.- 4.1.2 Impact of Product Quality.- 4.2 Free-Rectification Warranties in Finite Time.- 4.2.1 User's Replacement Cost.- 4.2.2 Manufacturer's Costs and Profit.- 4.2.3 Examples.- 4.3 Long-Life-Cycle, Pro-Rata Warranties.- 4.3.1 Cost Rates.- 4.3.2 Impact of Product Quality.- 4.4 Pro-Rata Warranties in Finite Time.- 4.4.1 Manufacturer's Supply Cost.- 4.4.2 Joint Distribution of BUf(t) and N(t).- 4.4.3 User's Replacement Cost.- 4.4.4 Manufacturer's Warranty Cost.- 4.4.5 Examples.- 5 Extended Warranties.- 5.1 Mathematical Model.- 5.1.1 Probability Distributions.- 5.2 Performance Measures.- 5.2.1 Profitability and Risk-of-Loss.- 5.2.2 Expected Cost and Profit.- 5.2.3 Expected Cost Per Unit Time.- 5.2.4 Multiple Extended Warranty Options.- 5.2.5 User's Perspective.- 5.3 Extensions.- 5.3.1 Extended Warranties for Used Systems.- 5.3.2 Free-Rectification Base Warranty.- 5.3.3 Random Repair.- 5.3.4 Adverse Selection and Moral Hazard.- 6 Preventive Maintenance.- 6.1 Long-Term-Average-Cost Models.- 6.1.1 Age-Replacement Strategy.- 6.1.2 Periodic-Replacement Strategy.- 6.1.3 Repair-Limit Strategy.- 6.2 Quality and Preventive Maintenance.- 6.2.1 Sufficient Conditions for Cost Reduction.- 6.2.2 Extent of Cost Reduction.- 6.3 Cost Models in Finite Time.- 6.3.1 Age-Replacement Strategy.- 6.3.2 Periodic-Replacement Strategy.- 6.3.3 Repair-limit Strategy.- 6.4 Maintenance After Warranty.- 6.4.1 Unit Contracts.- 6.4.2 Perpetual Contracts.