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Chap 10 Managing Engineering Design

Chap 10 Managing Engineering Design. Advanced Organizer. Chapter Objectives. Describe the phases or stages in systems engineering and the new product development process Recognize product liability and safety issues Recognize the significance of reliability and other design factors.

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Chap 10 Managing Engineering Design

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  1. Chap 10 Managing Engineering Design

  2. Advanced Organizer

  3. Chapter Objectives • Describe the phases or stages in systems engineering and the new product development process • Recognize product liability and safety issues • Recognize the significance of reliability and other design factors

  4. Eng. Design Process Nature of Engineering Design • Information: • Statement of the problem • Design standards • Design methods • Information: • Drawings • Specifications • Financial estimates • Written reports • Oral presentations

  5. Systems Engineering/New Product Development The design of a complex engineered system, from the realization of a need through production to engineering support in use is known as systems engineering (especially with military or space systems) or as new product development (with commercial systems).

  6. New Product Development - Stages • Conceptual • Technical Feasibility or Concept Definition • Development • Commercial Validation • Production • Product Support • Disposal Stage

  7. Systems Engineering Process(In each phase of development) • Requirements Analysis: Analyze customer needs, objectives, and constraints to determine the functional requirements. • Functional Analysis/Allocation Identify lower level functions needed to meet these functional requirements, and translate them into design requirements suitable as design criteria. • Synthesis. Define the system concept, configuration item alternatives and select the preferred set of product or process solutions to the level of detail required in the phase being conducted.

  8. Systems Engineering Process(In each phase of development) • System Analysis and Control. Provide the progress measurement, assessment, and decision mechanisms required to evaluate design capabilities and document the design and decision data. • Trade-off (trade) studies • Risk management • Configuration management • Interface management • Systems engineering master schedule (SEMS) • Technical performance measurement (TPM) • Technical (design) reviews

  9. Quality Function Deployment (QFD) • Quality function deployment is a team-based management tool in which the customer expectations are used to drive the product development process. • Conflicting characteristics or requirements are identified early in the QFD process and can be resolved before production.

  10. Quality Function Deployment (QFD) Key benefits: • product improvement, • increased customer satisfaction, • reduction in the total product development cycle, & • increased market share.

  11. Interrelationship between Technical Descriptors QFD: House of Quality How: Technical Descriptors (Voice of the Organization) Prioritized Customer Reqmts What: Customer Reqmts (Voice of Customer) Relationship between Requirements and Descriptors Prioritized Technical Descriptors

  12. Phase I: Product planning Phase II: Parts deployment Phase III: Process planning Phase IV: Production planning 4 Phases of QFD

  13. Matrix What How House of Quality Voice of Customer Tech. Performance Measures Subsystem Design Matrix Tech. Performance Measures Piece/Part Characteristics Piece/Part Design Matrix Piece/Part Characteristics Process Parameters Process Design Matrix Process Parameters Production Operations Classical Model of QFD

  14. Engineering Metrics • Brightness • Weight • Dimensions (girth + width) • Time/Tasks required to start • Distortion • Distance from presenter • Time to insert/pull-out slide • Attractive product • Customer Needs • Good image • Easy to transport • Keeps present. flowing • Image visible in bad conditions • Minimizes unplanned interruptions • Design makes the product attractive • Device sets up quickly • Works well for short present. QFD Example: Portable Slide Projector

  15. Engineering Metrics Time to insert/pull Attractive product Customer Weights Time/Tasks Dimensions Brightness Distortion Distance Weight Customer Requirements Good image 9 9 9 Easy to transport 9 9 9 Device sets up quickly 9 3 1 9 3 3 Works well for short present. 9 1 3 3 3 Keeps present. flowing 1 3 3 9 Image visible in bad conditions 3 9 Minimizes unplanned interruptions 1 3 1 9 Design makes the product attractive 3 3 3 9 Raw 108 117 108 114 27 72 81 58 score Relative 11% 4% 16% 17% 16% 17% 8% 12% Weight QFD Example: Portable Slide Projector—Phase I

  16. Part Characteristics Phase I Relative Weights Bottom case Condenser Heat sink Top case Stand Lamp Lens Engineering Metrics Brightness 16% 9 9 1 9 Weight 17% 9 9 1 1 3 Dimensions (girth + width) 16% 9 9 3 9 1 3 3 Time/Tasks required to start pres. 16% 3 3 Distortion 13% 9 9 1 1 Distance from presenter 8% 9 9 9 Time to insert/pull-out slide 10% 3 1 Attractive product 4% 9 9 9 Raw 3.6 3.3 4.4 2.7 1.3 4.9 1.1 score Rel. 6% 5% 13% 17% 15% 21% 23% Weight Rank 3 4 2 1 7 6 5 QFD Example: Portable Slide Projector—Phase II

  17. Phases in Systems Engineering / New Product Development(DoD) • Pre-milestone zero studies • Concept exploration & definition • Demonstration and validation • Engineering and manufacturing development • Production and deployment • Operations and support

  18. Phases in Systems Engineering / New Product Development(NASA) • Conceptual design studies • Concept definition • Design and development • Fabrication, integration, test, and certification • Pre-operations • Operations and disposal

  19. Phases in Systems Engineering / New Product Development (NSPE/NIST ) • Conceptual • Technical feasibility • Development • Commercial validation and production preparation • Full-scale production • Product support

  20. Tasks Within Each Phases of Systems Eng. / New Product Development • Approval to expend the resources / agreement on the work to be accomplished. • Accomplishment of the work • Compile the results: designs and specifications, analyses and reports, and a proposed plan for conducting the following phase if one is recommended. • To cancel the development, • To go back (recycle) and do more work in the present phase; or • To proceed with the next phase.

  21. Conceptual stage • Statement of the design problem, clearly defining what the desired intended accomplishment of the desired product • Key functions • Performance characteristics • Constraints • Criteria of judging the design quality

  22. Conceptual stage • Musts: requirements that must be met • Must nots: constraints defining what the system must not be or do • Wants: features that would significantly enhance the value of the solution but are not mandatory (to which an additional, even less compelling category of "nice to have" is often added) • Don't wants: characteristics that reduce the value of the solution

  23. Customer Satisfaction Delighters Actual Performance Dissatisfiers Satisfiers Conceptual stage(Kano’s Model)

  24. Expected Quality Dissatisfiers Smooth Surface Scratches, blemishes All parts work Broken parts Clear instruction Missing instruction Normal function Function not provided Product is safe to use Product is unsafe Product conforms to std. Product is non-conformant Conceptual stage(Kano’s Model)

  25. Desired Quality Performance Measure Direction Capacity Cubic feet of storage LargerTB Price Dollars SmallerTB Reliability MTBF LargerTB Speed Transactions /second LargerTB Conceptual stage (Kano’s Model) Satisfiers:

  26. Conceptual stage(Kano’s Model) • Examples of Delighters • Sony Walkman • 3M Post-it • Cup Holder • One-touch recording • Redial button on telephone • Graphic User Interface (GUI)

  27. Results from Conceptual stage • A set of functional requirements • Identification of the potential barriers to development, manufacturing, and marketing the proposed product. • Test-of-principle model to reduce technical uncertainties • Order-of-magnitude economic analyses and • Preliminary market surveys to reduce financial uncertainty.

  28. Importance of Conceptual stage • 1% of the cost of the product • 70 % of the life-cycle cost

  29. Technical feasibility stage The objectives of this stage are • To confirm the target performance of the new product through experimentation and/or accepted engineering analysis and • To ascertain that there are no technical or economic barriers to implementation

  30. Technical feasibility stage • Subsystem identification • Trade-off studies • System integration • Interface definition • Preliminary breadboard-level testing • Subsystem and system design requirements (reliability, safety, maintainability, and environmental impact). • Development of preliminary test plans, production methods, maintenance and logistic concepts, and marketing plans. • Preliminary estimation of the life-cycle cost of the system. • Preparation of a proposal for the development stage

  31. Importance of Technical feasibility stage • 7% of the cost of the product • 85 % of the life-cycle cost

  32. Development stage(Build-test-fix-retest sequences) The objective of this stage is • To make the needed improvements in materials, designs and processes and • To confirm that the product will perform as specified by constructing and testing engineering prototypes or pilot processes.

  33. Commercial validation and Production preparation stage The objective of this stage is to develop the manufacturing techniques and establish test market validity of the new product. • Selecting manufacturing procedures, production tools and technology, installation and start-up plans for the manufacturing process, and • Selecting vendors for purchased materials, components, and subsystems.  Reproduction prototypes

  34. Full-scale production stage • Final design drawings, specifications, flow charts, and procedures are completed for manufacture and assembly of all components and subsystems of the product, as well as for the production facility. • Quality control procedures and reliability standards are established • Contracts made with suppliers • Procedures established for product distribution and support. • Manufacturing facilities are constructed • Continuous process improvement (kaizen)

  35. Product support stage • Technical manuals for product installation, operation, and maintenance • Training programs for customer personnel • Technical supports • Warranty services • Repair parts and replacement consumables must be manufactured and distributed • New procedures for operation and maintenance • Improved parts for retrofit • Notification of product recall for safety reasons

  36. Disposal stage • Every product causes waste during manufacture, while in use, and at the end of useful life that can create disposal problems. • The time to begin asking, "how do we get rid of this" is in the early stages of product or process design.

  37. CONCURRENT ENGINEERING AND CALS

  38. Traditional Product Development • System Level Design • Subsystem Design • Component Design • Manufacturing Process Concept Development • Manufacturing Process Development • Delivery Development • Service Development • Delivery

  39. Concurrent Processes System Level Design Manufacturing Process Concept Development Delivery Development Subsystem Design Service Development Manufacturing Process Development Component Design Production & Delivery

  40. Definition of Concurrent Engineering A systematic approach to the integrated, concurrent design of products and their related processes, including manufacture and support. This approach is intended to cause the developer, from the outset, to consider all elements of the product lifecycle from concept through disposal, including quality control, cost, scheduling, user requirements. (Inst. For Defense Analysis)

  41. Advantages of Concurrent Engineering The set of methods, techniques, and practices that: • Cause significant consideration within the design phases of factors from later in the life cycle; • Produce, along with the product design, the design of processes to be employed later in the life of the product; • Facilitate the reduction of the time required to translate the design into distributed products; and • Enhance the ability of products to satisfy users' expectations and needs.

  42. CALS • "Computer Aided Logistics Support," then • "Computer-aided Acquisition and Logistics Support," • "Continuous Acquisition and Life-Cycle Support," (1993, DoD) • "Commerce At Light Speed" (U.S. industry)

  43. Purposes of CALS To enable more effective generation, management, and use of digital data supporting the life cycle of a product through the use of international standards, business process change, and advanced technology application.

  44. CALS Electronic storage, transmission, and retrieval of digital data • Between engineers representing the several design stages, • Between organization functions such as marketing, design, manufacturing, and product support, and • Between cooperating organizations such as customer and supplier.

  45. Commercial standards • Computer Graphics Metafile (CGM) (ISO-8632): A standard means of representing line drawings in a device-independent way. • Electronic Data Interchange for Administration, Commerce, and Transport (EDIFACT) (ISO 9735, ANSI X12): An international standard means for communicating commercial (trade) information. • Initial Graphics Exchange Specification (IGES) (ANSI Y14.26M): A standard means of representing product data in a device-independent way.

  46. Control Systems in Design • Drawing/Design Release • Version Control • Product Data Management (PDM) • Configuration (Design Criteria) Management • Functional baseline (at end of conceptual stage) • Allocated baseline (at end of validation stage) • Product baseline (at end of development stage) • Design Review

  47. Special Considerations in Design • Product liability • Safety • Reliability • Maintainability • Availability • Ergonomics • Producibility

  48. History of Product Liability • Caveat emptor (let the buyer beware) • “Privity of contract” (Direct contractual relationship) • 1916, MacPherson v. Buick (No need for direct contract) • Plaintiff must prove negligence • 1960, Hernington v. Bloomfield Motors, implied warranty • 1984, Greenman v. Yuba Power Product Strict Liability • Absolute liability: “A manufacturer could be held strictly liable for failure to warn of a product hazard, even if the hazard was scientifically unknowable at the time of the manufacture and sale of the product.”

  49. Reducing Liability • Include safety as a primary specification for product design. • Use standard, proven materials and components. • Subject the design to thorough analysis and testing. • Employ a formal design review process in which safety is emphasized. • Specify proven manufacturing methods. • Assure an effective, independent quality control and inspection process. • Be sure that there are warning labels on the product where necessary.

  50. Reducing Liability • Supply clear and unambiguous instructions for installation and use. • Establish a traceable system of distribution, with warranty cards, against the possibility of product recall. • Institute an effective failure reporting and analysis system, with timely redesign and retrofit as appropriate. • Document all product safety precautions, actions, and decisions through the product life cycle.

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