Reliability Performance and Specifications in New Product Development T. Østeras1, D.N.P. Murthy2 and M. Rausand3 1 Associate Professor of Design Engineering, the Norwegian University of Science and Technology, Trondheim, Norway. 2 Professor of Engineering and Operations Management, The University of Queensland, Australia and Senior scientific Advisor, Norwegian University of Science and Technology, Trondheim, Norway. 3 Professor of Safety and Reliability Engineering, the Norwegian University of Science and Technology, Trondheim, Norway Preface The establishment of a framework for Reliability Performance and Specifications in New Product Development is the objective of a joint research project between University of Queensland and the Norwegian University of Science and Technology. The project is divided into three parts: • Part I: Establish a conceptual framework for determining reliability specifications and assessing reliability performance in new product development. • Part II: Discuss briefly the tools and techniques needed in the above framework. • Part III: Conduct case studies. This report documents the results from Parts I and II of the research project. The conceptual framework presented in Part I provides the basis for Part II of the research project which deals with the tools and techniques needed. Reliability Performance and Specifications in New Product Development T. Østeras1, D.N.P. Murthy2 and M. Rausand3 Part I: A Conceptual Framework 1 Associate Professor of Design Engineering, the Norwegian University of Science and Technology, Trondheim, Norway. 2 Professor of Engineering and Operations Management, The University of Queensland, Australia and Senior Scientific Advisor, Norwegian University of Science and Technology, Trondheim, Norway. 3 Professor of Safety and Reliability Engineering, the Norwegian University of Science and Technology, Trondheim, Norway. Table of Contents 1 INTRODUCTION................................................................................................1 2 PRODUCTS..........................................................................................................3 2.1 PRODUCT CLASSIFICATION .............................................................................3 2.2 PRODUCT DECOMPOSITION .............................................................................7 2.3 PRODUCT LIFE CYCLE.....................................................................................9 2.3.1 Manufacturer’s Point of View................................................................9 2.3.2 Buyers’ Point of View ..........................................................................10 3 PRODUCT PROPERTIES AND PERFORMANCE.....................................11 3.1 DEFINITIONS .................................................................................................11 3.1.1 Product Properties...............................................................................11 3.1.2 Product Performance...........................................................................13 3.2 PRODUCT PERFORMANCE: DIFFERENT PERSPECTIVES ..................................15 3.2.1 Buyer's Perspective..............................................................................15 3.2.2 Manufacturer's Perspective .................................................................16 3.2.3 Product Life Cycle (PLC) Perspective.................................................17 3.3 PRODUCT QUALITY AND CUSTOMER SATISFACTION.....................................19 3.3.1 Product Quality....................................................................................19 3.3.2 Customer Satisfaction ..........................................................................19 3.4 PRODUCT COST.............................................................................................23 3.4.1 Manufacturers’ versus Buyers’ Perspective ........................................23 3.4.2 Operating Cost versus Product Performance......................................24 4 NEW PRODUCT DEVELOPMENT (NPD) PROCESSES...........................26 4.1 DRIVERS FOR NPD........................................................................................26 4.2 NPD PHASES.................................................................................................27 4.2.1 Front-End [Phase 1]............................................................................27 4.2.2 Design [Phases 2 and 3]......................................................................28 4.2.3 Development [Phases 4 and 5] ............................................................29 4.2.4 Production [Phase 6]...........................................................................29 4.2.5 Testing..................................................................................................30 4.3 AN ALTERNATIVE MULTILEVEL CHARACTERISATION ..................................30 4.4 EVALUATIONS AND ITERATIONS ...................................................................31 4.5 DECISION-MAKING .......................................................................................34 4.6 DATA AND INFORMATION FLOW ...................................................................35 5 PRODUCT SPECIFICATION.........................................................................37 5.1 CONCEPT AND DEFINITION............................................................................37 5.2 RELATIONSHIP BETWEEN OBJECTIVE AND PERFORMANCE............................39 5.3 RELATIONSHIP BETWEEN PERFORMANCE AND SPECIFICATION .....................40 5.4 PERFORMANCE AND SPECIFICATION LINKS IN THE NPD PROCESS................41 5.4.1 Stage I ..................................................................................................41 5.4.2 Stage II.................................................................................................42 6 CONCEPTUAL MODEL FOR PRODUCT SPECIFICATION ..................44 6.1 FRONT-END PHASE (STAGE I, LEVEL I) ........................................................44 6.2 DESIGN PHASES (STAGE I, LEVELS II AND III) ..............................................45 - i - 6.3 DEVELOPMENT PHASES (STAGE II, LEVELS II AND III).................................47 6.4 PRODUCTION (STAGE II, LEVEL I).................................................................47 6.5 FACTORS INFLUENCING OBJECTIVE AND PERFORMANCE..............................48 6.5.1 Objective ..............................................................................................48 6.5.2 Desired Performance [DP-I]...............................................................49 6.5.3 Predicted Performance ........................................................................50 6.5.4 Actual Field Performance....................................................................50 6.5.5 Overview of Factors Influencing Product Performance......................51 7 PRODUCT RELIABILITY ..............................................................................53 7.1 DEFINITION OF RELIABILITY .........................................................................53 7.2 PRODUCT DEGRADATION AND FAILURES......................................................53 7.2.1 Failures Related to Functions..............................................................54 7.2.2 Failure Modes......................................................................................56 7.2.3 Failure Causes and Severity ................................................................58 7.2.4 Deterioration........................................................................................60 7.3 MAINTENANCE AND MAINTAINABILITY........................................................61 7.3.1 Maintenance Actions............................................................................61 7.3.2 Maintenance Costs...............................................................................62 7.3.3 Maintainability.....................................................................................63 7.4 CONSEQUENCES OF FAILURES.......................................................................64 7.4.1 Customers Point of View......................................................................64 7.4.2 Manufacturers Point of View...............................................................66 7.5 PRODUCT RELIABILITY .................................................................................66 7.5.1 Life Cycle Perspective..........................................................................66 7.5.2 Product Profitability Perspective ........................................................68 7.6 CHARACTERISATION OF PRODUCT RELIABILITY ...........................................69 7.6.1 First Failure.........................................................................................69 7.6.2 Subsequent Failures.............................................................................71 7.6.3 Failures over Time...............................................................................72 7.6.4 Availability...........................................................................................73 8 RELIABILITY SPECIFICATIONS................................................................75 8.1 INTRODUCTION .............................................................................................75 8.2 LITERATURE REVIEW....................................................................................75 8.2.1 Selecting the Desired Reliability