STRENGTH OF THE ANTERIOR VERTEBRAL SCREW FIXATION IN RELATION TO BONE MINERAL DENSITY

1
Biomechanical Design(051083)

• Lecturer
• - Tae-Hong Lim, Ph.D.
• 1420 Seamans Center
• 335-5810 (office) talim_at_engineering.uiowa.edu
  (email)
• - David Wilder, PhD and Nicole Grossland, PhD
• Office Hours
• M, W, F 400 500 PM
• Appointment
• Pre-requisites
• 57007 Statics
• 57019 Mechanics of Deformable Bodies
• 51050 Biomechanics

2
Text and Grading

• Text
• The Mechanical Design Process, 3rd Edition
• David G. Ullman
• McGraw-Hill (ISBN 0-07-237338-5)
• Grading
• 15 Homework and Quiz
• 20 Individual Design Notebook
• 10 Reverse engineering report
• 40 Team Project
• 15 Final Exam
• Final exam will be a short answer exam covering
  the terminology and concepts studied throughout
  this course

3
Individual Design Notebooks

• You are to keep a design notebook for use in this
  course.
• This is to be a spiral bound notebook.
• Every page must be numbered at the beginning of
  the term.
• No pages can be removed and each page must be
  dated and initialed when used.
• All work related to this course (homework and
  design project) will be entered into this note
  book.
• Each notebook will be collected at the end of the
  term and graded on the number of quality
  entries it contains.
• A quality entry is a significant sketch or
  drawing of some aspect of design a listing of
  functions, ideas or other features a table such
  as morphology or decision matrix or a page of
  text.
• Unintelligible entries are not quality entries.

4
Team Project

• Design Team
• Design teams will be organized by the instructor.
• Team members will determine the leader (CEO).
• Team Project
• Each team will determine a design problem (new
  invention or modification) related to
  biomechanical devices through discussion with the
  instructor.
• The team project will be considered completed by
  obtaining final product documentation (drawings,
  part list with specified materials, and assembly
  instructions).
• No final product in physical form is required.
• Each team should record the whole history of the
  design in the Product Development File (PDF).

5
Documents in the PDF

• Problem Appraisal Phase
• Understanding the Problem
• Description of Customers
• Customers Requirements
• Weighting of Customers Requirements
• Competitions Benchmarks vs. Customers
  Requirements
• Engineering Requirements
• Competitions Benchmarks vs. Engineering
  Requirements
• Engineering Targets
• Planning the Project
• Task Titles
• Objectives of Each Task
• Personnel Required for Each Task
• Time Required for Each Task
• Schedule of Tasks

• Conceptual Design Phase
• Concept Generation
• Function Decomposition
• Literature and Patent Search Process and Results
• Function-Concept Mapping
• Sketches of Overall Concepts
• Concept Evaluation and
• Assessment of Tech. Readiness
• Identification of Failure Modes
• Identification of Critical Parameters
• Concept Selection
• Decision Matrices to Determine Best Concepts
• Analsysi, Experiments and Models Supporting
  Evaluation

• Product Design Phase
• Product Generation
• Usable off-the-shelf Products
• Shape Development Driven by Function
• Materials Selection
• Manufacturing Process Selection
• Product Evaluation
• Comparison to Engineering Function
• Functional Changes Noted
• Design for Assembly Evaluation
• Cost Evaluation
• Analysis, Experiments and Models Supporting
  Evaluation
• Final Product Documentation
• Layout Drawings
• Detail Drawings of Manufactured Parts
• Parts List (Bill of Materials)

The file is to be maintained by the group in a
binder. This PDF, when completed, is effectively
a final report. It will be graded on
completeness and quality of both the design and
the documentation itself.
6
Biomechanical Design

• Design
• Deliberate purposive planning
• A mental project or scheme in which means to an
  end are laid out
• A preliminary sketch or outline showing the main
  features of something to be executed
  DELINEATION
• The arrangement of elements or details in a
  product or work of art
• The creative art of executing aesthetic or
  functional designs
• Biomechanical Design
• Design something related to biomechanics, such
  as
• Biomechanical devices
• Medical devices orthopedic implants, scissors,
  scalpers, staplers, etc.
• Exercising devices treadmill, weight-lifting,
  helmets, wrist-guards, etc.
• Rehabilitation devices wheel-chairs, canes,
  etc.
• Biomechanical activities
• Exercises for fitness or strengthening body parts
• Biomechanical design includes
• Development (or invention) of new biomechanical
  stuffs and
• Modification of existing biomechanical stuffs

7
What will we learn in this class?

• Typical design process
• Identification of design problems
• Design
• Evaluation of the design
• Decision making
• Final report
• Techniques helping generate better quality
  designs in less time
• Concurrent engineering
• Computer aided drawing
• Legal and regulation issues
• Safety and liability
• Patent, FDA, CE, and UL
• Importance of communication of design data
• Records of design data, design process, and final
  report
• Oral presentations

8
The Life of A Product
Process of idea development, production, use,
and end of product life. The whole process must
be considered in the design process.
9
Design Process

• What is the design process?
• Design process is the organization and management
  of people and the information they develop in the
  evolution of the product.
• Why study the design process?
• Design process determines the efficiency of new
  product development.
• 85 of the problems with new products not working
  as intended, taking too long to bring to market,
  or costing too much are the result of poor design
  process.
• The design process needs to improved consistently
  and executed for developing better products
  because
• There is a continuous need for new,
  cost-effective, high-quality products.
• Most products require a team of people from
  diverse areas of expertise to develop an idea
  into hardware.
• We will study the design process to get the tools
  to develop an efficient design process regardless
  of the product being developed.
• 3 types of knowledge used by designers
• Knowledge to generate ideas
• Experience and natural ability
• Knowledge to evaluate ideas
• Experience and formal training (focus of most
  engineering education)
• Knowledge to structure the process
• Non-domain-specific knowledge
• What we will study in this class

10
History of the Design Process

• One person, with sufficient knowledge of the
  physics, materials and manufacturing processes to
  manage all aspects of the design and construction
  of the project, could design and manufacture an
  entire product in the past.
• By the middle of the 20th century, products and
  manufacturing processes had become too complex
  for one person to have sufficient knowledge or
  time to focus on all aspects of the evolving
  product.
• Different groups of people for marketing, design,
  manufacturing and overall management
• One-way communication over the wall
• What is manufactured is not often what the
  customer had in mind.
• Inefficient, costly, and greater possibility for
  making poor-quality products

11
History of the Design Process

• Simultaneous Engineering (in late 1970s and early
  1980s)
• Simultaneous development of the manufacturing
  process with the evolution of the product by
  assigning manufacturing representatives to be
  members of design team
• Concurrent Engineering (in late 1980s)
• Integrated Product and Process Design (IPPD) in
  the 1990s
• A greater refinement in thought about what it
  takes to efficiently develop a product
• Primarily focusing on the integration of teams of
  people, design tools and techniques, and
  information about the product and the processes
  used to develop and manufacture it.
• 10 Key Features of Concurrent Engineering
• Focus on the entire product life (chap 1)
• Use and support of design team (chaps 3 and 5)
• Realization that the processes are as important
  as the product (chaps 4 and 5)
• Attention to planning for information-centered
  tasks (chap 5)
• Careful product requirements development (chap 6)
• Encouragement of multiple concept generation and
  evaluation (chaps 7 and 8)
• Awareness of the decision-making process (chap 8)
• Attention to designing in quality during every
  phase of the design process (throughout)
• Concurrent development of product and
  manufacturing process (chaps 9-13)
• Emphasis on communication of the right
  information to the right people at the right time
  (throughout)
• A key point of concurrent engineering is a
  concern for information.
• Drawings, plans, concept sketches, meeting notes,
  etc.

12
Controllable Variables in Concurrent Engineering
13
Overview of the Design Process
14
Design Problems

• Design a joint to fasten together two pieces of
  1045 sheet steel (4 mm thick and 6 cm wide),
  which are lapped over each other and loaded with
  100 N?
• Ill-defined design problem with number of
  potential problems
• How to connect the sheets? (Bolted, glued,
  welded, etc.?)
• Disassembly required later?
• What working environment?
• etc.

What size SAE grade 5 bolt should be used to
fasten together two pieces of 1045 sheet steel (4
mm thick and 6 cm wide) which are lapped over
each other and loaded with 100 N? - Well defined
analysis problem finding the diameter of the bolt
HWK1 Change a problem from one of your
engineering science classes into a design problem
by changing as few words as possible. Do your
home work in your design notebook. Due is one
week.
15
Design problems have many satisfactory solutions
and no clear best solution.

• Design problems
• are ill-defined
• have no correct answer
• have no clear best answer.
• Design process knowledge is based upon the domain
  knowledge.

Mechanical design problems begin with an
ill-defined need and result in a piece of
machinery that behaves in a certain
way. PARADOX A designer must develop a machine
that has the capabilities to meet some need that
is not fully defined.
16
Basic Actions of Design Problem Solving

• ESTABLISH the need or realize that there is a
  problem to be solved.
• New needs also can be established throughout the
  design effort because new design problems arise
  as the product evolves. Design of these details
  poses new subproblems.
• PLAN how to solve the problem.
• Planning occurs mainly at the beginning of a
  project. Plans are always updated because
  understanding is improved as the process
  progresses.
• UNDERSTAND the problem by developing requirements
  and uncovering existing solutions for similar
  problems.
• Formal efforts to understand new design problems
  continue throughout the process. Each new
  subproblem requires new understanding.
• GENERATE alternative solutions.
• Concept Generation vs. Product Generation
• EVALUATE the alternatives by comparing them to
  the design requirements and to each other.
• Evaluation techniques also depend on the design
  phase there are differences between the
  evaluation techniques used for concepts and those
  used for products.
• DECIDE and acceptable solutions
• Decision making requires a commitment based upon
  incomplete evaluation.
• Decision requires a consensus of team members.
• COMMUNICATE the results
• Communication of the information developed to
  others on the design team and to management is an
  essential part of concurrent design.

17
Basic Terminologies used to describe the Design
Process

• Communication as a one key feature of
  concurrent engineering
• Communication depends on a shared understanding
  of terminology.
• Function
• What a product or a system is supposed to do
• Described using action verbs and a noun
  describing the object on which the action occurs
• Record images quantify the blood pressure fix
  an unstable spine segment etc.
• System
• A grouping of objects that perform a specific
  function
• Shutter system timer system CD-R system
  cooling system etc.
• A system can be decomposed into another
  subsystems or further into individual components
  (or parts).
• Multiple systems can be assembled into a higher
  level system or further into a final product.
• Feature the important form and function aspects
  of mechanical devices
• dimensions, material properties, shapes, or
  functional details (speed of opening and closing
  for shutter system)

In general, during the design process, the
function of the system and its decomposition are
considered first. After the function has been
decomposed to the finest subsystems possible,
assemblies and components are developed to
provide these functions.
Decomposition of design disciplines
18
Function, Behavior, and Performance

• Function
• describes what a device does.
• But, function provides no information about how a
  device accomplishes the function.
• Form
• The term form relates to any aspect of physical
  shape, geometry, construction, material, or size.
• provides some information on how a device
  accomplishes the function.
• Behavior and Performance in association with
  Function.

• Function is the desired output from a system yet
  to be designed.
• Behavior is the actual output, the response of
  the systems physical properties to the input
  energy or control.
• Performance is the measure of function and
  behavior how well the device does what it is
  designed to do.
• A clear picture of desired performance should
  developed in the beginning of the design process.

19
Types of Mechanical Design Problems

• Selection Design
• choosing one item (or more) from a list of
  similar items
• choosing a bearing, bolt, motor, etc. from a
  catalog
• Configuration Design
• How to assemble all the components into the
  completed product
• Parametric Design
• Finding values for the features that characterize
  the object being studied or that meet the
  requirements
• Design a cylindrical tank V ?r2l, determine r
  and l for known V
• Original Design
• Design a process, assembly or component not
  previously in existence
• Redesign
• Redesign of an existing product
• Most design problems are redesign problems since
  they are based on prior, similar solutions.
  Conversely, most design problems are original as
  they contain something new that makes prior
  solutions inadequate.

20
Languages of Mechanical Design

• A mechanical object can be described by
• Semantic language
• Verbal or textual representation of the object
• bolt or The shear stress is equal to the shear
  forces on the bolt divided by the x-sectional
  area.
• Graphical language
• drawing of the object
• Sketches, scaled representations of orthogonal
  drawings, or artistic renderings
• Analytical Language
• Equation, rules, or procedures representing the
  form of function of the object
• ? F/A
• Physical Language
• Hardware or physical model of the project
• - In most cases, the initial need is expressed in
  a semantic language as a written specification or
  a verbal request by a customer or supervisor, and
  the final result of the design process is a
  physical product.

21
Design, State, Constraints and Decision

• Design State
• Collection of all the knowledge, drawings,
  models, analyses and notes thus far generated
• In the beginning, design state is just the
  problem statement
• Design Constraints
• Factors limiting the design process
• Examples size, strength of material, corrosion
  properties, anatomy, etc.
• In the beginning, the design requirements
  effectively constrains the possible solutions to
  a subset of all possible product designs.
• Two sources of constraints added during the
  design process
• Designers knowledge of mechanical devices and
  the specific problem being solved
• Result of design decisions
• Design Decision
• Continuous comparison between design state and
  the goal (requirements for the product given in
  the problem statement)
• The difference controls the process.
• Design is the successive development and
  application of constraints until only one unique
  products remains.
• Each design decision changes the design state.
• The design progresses in increment punctuated by
  design decisions.

22
The Value of Information
The most valuable information is the decisions
that are communicated to others.
23
Design as Refinement of Abstract Representations
See Table 2.2 for levels of abstraction in other
languages.
Graphical Refinement
24
Information-processing Model of Human Problem
Solving
Information-Processing System used by the human
mental system in solving any type of problem
25
Chunks of Information
26
Information-processing Model of Human Problem
Solving

• Types of Knowledge that might be in a chunk of
  information
• General knowledge
• Information that most people know and apply
  without regard to a specific domain
• red is a color. 4 is bigger than 3.
• Gained through everyday experiences and basic
  schooling
• Domain Specific Knowledge
• Information on the form or function of an
  individual object or a class of objects
• Bolts are used to carry shear or axial stress
• The proof stress of a grade 5 bolt is 85 kpsi.
• Gained from study and experience in the specific
  domain
• It may take about 10 years to gain enough
  specific knowledge to be considered an expert in
  a domain
• Procedural Knowledge
• The knowledge of what to do next
• If there is no answer to problem X, then
  decompose X into two independent subproblems of
  x1 and x2 that are easier to solve.
• Gained mostly from experience
• Required for solving mechanical design problems

27
Implications of the Information-processing Model

• The size of STM is a major limiting factor in the
  ability to solve problem.
• To accommodate this limitation, breakdown
  problems into finer and finer subproblems until
  we can get our mind around it
• in other word, manage the info in our STM
• Human designers are quite limited although our
  expertise about the constraints and potential
  solutions increases and our configuration of
  chunks becomes more efficient as we solve
  problems.
• These limitations would preclude our ability to
  solve complex problems.

28
Mental Processes that Occur during Design

• Understanding the problem
• A problem is understood by comparing the
  requirements on the desired function to
  information in the long-term memory.
• Every designers understanding of the problem is
  different, we need to develop a method to ensure
  that the problem is fully understood with minimal
  bias from the designers own knowledge.
• Generating a solution
• Use the information stored in LTM that meets the
  design requirements.
• If no solution found from LTM, then use a three
  step approach
• Decompose the problem into subproblems
• Try to find partial solutions to the subproblems
• Recombine the subsolutions to fashio a total
  solution
• Creative part of this approach is in knowing how
  to decompose and recombine cognitive chunks
• Evaluating the solution
• Evaluation requires comparison between generated
  ideas and the laws of nature, the capability of
  technology and the requirements of the design
  problem itself.
• Evaluation requires modeling the concept to see
  how it performs.
• The ability to model is usually a function of
  knowledge in the domain.
• Deciding
• A decision is made at the end of each
  problem-solving activity to accept the generated
  and evaluated idea or to address another topic
  that is related to the problem.
• Controlling the design process
• Path from initial problem to solution seemed
  random.

29
Problem-Solving Behavior

• A persons problem-solving behavior affects how
  problems are solved individually and has a
  significant impact on team effectiveness.
• Four Personal-Problem Solving Dimensions (or
  styles)
• Individual Problem-solving Style
• Introvert
• Solve problem internally (reflective) a good
  listener think and speak enjoy having time
  alone for problem solving
• Extrovert
• Sociable tend to speak and think
• About 75 Americans and 48 of engineering
  students and executives
• Individual Preference to work with Facts or
  Possibilities
• Facts oriented people
• literal, practical, and realistic
• 75 of Americans, 66 of top executives, 34 of
  all engineering students
• Possibility oriented people
• Like concepts and theories and look for
  relationship between pieces of information and
  meaning of the information
• Objectivity with which decisions are made
• Objective
• Logical, detached and analytical
• Taking objective approach to make decisions
• 51 of Americans, 68 of engineering students,
  95 of top executives

• Please make sure to read section 3.3.6 carefully
  for better design team activities.

30
Characteristics of a Creative Designer

• Problem solving involves
• Understanding the problem, generating solutions,
  evaluating the solutions, deciding on the best
  one, and determining what to do next
• Criteria of Creative Solution
• It must solve the design problem.
• It must be original.
• Originality and creativity are assessed by
  society.
• Creativity in relation to other Attributes
• Intelligence no correlation with creativity
• Visualization Ability
• Creative engineers have good ability to
  visualize, to generate and manipulate visual
  images in their head.
• The ability to manipulate complex images can be
  improved with practice and experience.
• Knowledge
• A person must have knowledge of existing products
  to be a creative designer
• A firm foundation in bioengineering science is
  essential to being a creative biomechanical
  designer.
• Partial Solution Manipulation important
  attribute
• Risk Taking certainly required
• Conformity Creative people tend to be
  nonconformists.
• Constructive nonconformists take a stand because
  they think they are right and might generate a
  good idea.
• Obstructive nonconformists take a stand just to
  have an opposing view and will slow down the
  design progress.

31
Creative Designer

• A creative designer is a
• Visualizer
• Hard worker and
• Constructive nonconformist with knowledge about
  the domain and ability to dissect things in his
  or her head
• Good News
• Designers with no strong natural ability can
  develop creative methods by using good
  problem-solving techniques to help decompose the
  problems in ways that maximize the potential for
  understanding it, for generating good solutions,
  for evaluating the solutions, for deciding which
  solution is best and for deciding what to do next
• A design project requires
• much attention to detail and convention
• demands strong analytical skills and thus
• People with a variety of skills.
• There are many good designers who are not
  particularly creative individuals.

32
Engineering Design Team

• A team is a group of people working toward a
  common understanding.
• Team vs. Individual Problem Solving
• There are social aspects of team work.
• Each team member may have different understanding
  of the problem, different alternatives for
  solving it, and different knowledge for
  evaluating it. (more solutions but also more
  confusion)
• Team Goals
• A small number of people with complementary
  skills who are committed to a common purpose,
  common performance goals and a common approach
  for which team members hold themselves mutually
  accountable are required for an effective team.
• Team members must
• learn how to collaborate with each other, i.e.,
  to get the most out of other team members.
• Comprise to reach decisions through consensus
  rather than by authority.
• Establish communications.
• Be committed to the good of the team.
• Team Roles
• Organizer Creator Resource-investigator
  Motivator Evaluator Team worker Solver
  Completer (finisher or pusher)
• Building Team Performance
• For developing productive teams
• Keep the team productive
• Select team members on the basis of skills in
  both primary and secondary roles
• Establish clear rule of behavior
• Set and seize upon a few immediate
  performance-oriented goals.

33
Overview of the Design Process
An Ideal Flow Chart of Activities During Design
Process
34
What initiates a Design Project?

• Need for a New Design
• Market
• About 80 of new product development is
  market-driven.
• Assessment of the market is most important in
  understanding the design problem because there is
  no way recover the costs of design and
  manufacture without market demand.
• Incorporation of the latest technology can
  improve its perception as a high quality product.
• New product idea without market demand
• To use new technologies whose development
  requires an extensive amount of capital
  investment and possibly years of scientific and
  engineering time
• High financial risk but greater profit due to
  uniqueness
• Examples of successful products sticky notes
  Walkman
• Need for Redesign
• By market demand for a new model
• Desire to include a new technology
• Fix a problem with an existing product
• Redesign process can be applied to the
  subproblems that result from the decomposition of
  a higher-level system.

35
Overview of the Design Process

• Project Planning
• to allocate the resources of money, people, and
  equipment to accomplish the design activities
• Planning should precede any commitment of
  resources although requiring speculations about
  the unknowns
• Easier to plan a project similar to earlier
  projects than to plan a totally new one
• Plans are often updated whenever unknown demands
  become certain with the progress of design
  project
• Specifications Definition
• Goal is to understand the problem and to lay the
  foundation for the remainder of the design
  project.
• Identify the customers Generate the customers
  requirements Evaluate the competition Generate
  engineering specifications Set targets for its
  performance
• Design Review
• formal meeting for progress report and
  design-decision making
• Conceptual Design
• To generate and evaluate the concepts for the
  product
• Generate concepts based on the defined
  specifications for developing a functional model
  of the product
• Evaluate concepts by comparing the concepts
  generated to the targets for its performance
• Design Review
• Product Development
• Evaluate the product for performance, cost, and
  production
• Make product decisions

36
Why Do We Have to Follow The Design Process
Techniques?

• Paradox
• Techniques in the design process may imply
  RIGIDITY whereas the creativity implies
  FREEDOM.
• Following the techniques in the design process
  helps the designers develop a quality product
  that meets the needs of the customer by several
  ways
• Eliminating expensive changes later
• Developing creative solutions to design problems
  systematically
• Creativity does not spring from randomness.
• Genius is 1 percent inspiration and 99 percent
  perspiration.
• The inspiration for creativity can only occur if
  the perspiration occur early is properly directed
  and focused.
• The techniques that make up the the design
  process are only an attempt to organize the
  perspiration.
• Forcing documentation of the progress of the
  design (record of the designs evolution) that
  will be useful later in the design process.

37
Design Process Examples
Simple Process
Complex Process
38
Communication during the Design Process

• Design Records
• Importance of documents in design file
• To demonstrate the state-of-the-art design
  practices
• To prove originality in case of patent
  application
• To demonstrate professional design procedures in
  case of a lawsuit
• Design Notebook
• A diary of the design tracking the ideas
  development and the decision made in a design
  notebook
• Name Affiliation Title of the problem Problem
  Statement and all sketches, notes and
  calculations that concerns the design
• A design notebook sequentially numbered, signed
  and dated pages is considered good documentation
  whereas random bits of information scrawled on
  bits of papers are not.
• Good evidences for legal purposes (patent or
  lawsuit) as well as a reference to the history of
  the designers own work
• Documents Communicating with Management
• Needed for periodic presentations to managers,
  customers, and other team members for design
  review
• Regardless of its form (oral or written)
• Make it understandable (consider the recipients
  level of knowledge about the design problem)
• Carefully consider the order of presentation
  (whole parts whole 3-step approach gradual
  introduction of new ideas)
• Be prepared with quality material (good visual
  and written documentation following the agenda
  being ready for questions)
• Documents Communicating the Final Design
• Material describing the final design, e.g,
  Drawings (or data files) of individual components
  and of assemblies

39
Team Project

• Select an original design problem to solve
  throughout the remainder of the course.
• The problem should concern biomechanical devices
  in which some of the design team members have
  some knowledge or training.
• The final product will be data from analyses and
  evaluation and final drawings, not an actual
  hardware.
• Design Team Activity
• Each student should start gathering the design
  ideas immediately and recording the ideas in the
  design notebook.
• Start the team meeting ASAP for
• Organization of the team
• Planning the design process to finish the project
  by the end of April.
• Each team will present their design project in
  May.

Any discussion about the design project with the
instructor is welcome.
40
Project Definition and Planning

• Concurrent engineering encourages involvement
  through out the entire product life cycle from
  the project definition to product retirement.
• Project definition and planning is the first
  phase of the mechanical design process.

41
Project Definition

• Why developing new products?
• To fill some market need
• Mostly driven by the customer
• To exploit a technological development
• Driven by new technologies and what is learned
  during the design
• Project Definition
• the challenges of choosing from the many
  suggestions as to which products to spend time
  and money on to develop or refine
• Fuzzy front end of dealing with vague design
  ideas
• Specific Questions in Project Definition Phase
• Is there a good potential return on investment
  (ROI)?
• Does the new product or improvement fit the
  company image?
• Does it fit the distribution channels?
• Is there sufficient production capacity in-house
  or with known vendors?
• What will the project cost?

42
Project Planning

• Planning is like trying to measure the smile of
  the Cheshire cat you are trying to quantify
  something that isnt there.
• Planning is the process used to develop a scheme
  for scheduling and committing the resources of
  time, money, and people.
• Producing a map showing how product design
  process activities are scheduled.
• The whole activities of specification definition,
  conceptual design, and product development must
  be scheduled and have resources committed to them
• Planning generates a procedure for developing
  needed information and distributing it to the
  correct people at the correct time.
• Important information product requirements,
  concept sketches, system functional diagrams,
  component drawings, assembly drawings, material
  selections, and any other representation of
  decisions made during the development of the
  product.
• Typical Master Plan (a generic process) of a
  Company for Specific Products
• A blue print for a process
• product development process delivery process
  new product development plan or product
  realization plan, etc.
• We will refer to this generic process as the
  product development process (PDP).

43
ISO-9000

• A quality management system of the International
  Standard Organization
• First issued in 1987 and now adopted by over 150
  countries
• Over 350,000 companies worldwide and 8500 U.S.
  companies have the ISO-9000 certification
• ISO-9000 registration means that the company has
  a quality system that
• Standardizes, organizes, and controls operations.
• Provides for consistent dissemination of
  information.
• Improves various aspects of the business-based
  use of statistical data and analysis.
• Enhances customer responsiveness to products and
  services.
• Encourage improvement.
• To receive certification,
• One should develop a process that describes how
  to develop products, handle product problems, and
  interact with customers and vendors.
• Required written procedures that
• Describe how most work in the organization gets
  carried out (i.g., the design of new products,
  the manufacture of products, and the retirement
  of products).
• Control distribution and reissue of documents.
• Design and implement a corrective and protective
  action system to prevent problems from recurring.
• Evaluation of the effectiveness of the process by
  an accreditted external auditor
• Certification expires in 3 years and audits at
  6-month intervals to maintain the currency of the
  certificate.
• ISO-9000 requires a company to have a documented
  development process on which the plan for a
  particular product can be based.

44
Background for Developing a Design Project Plan

• A plan tells how a project will be initiated,
  organized, coordinated, and monitored, e.g.,
  managerial activities.
• Types of Design Projects
• Variation of existing product
• Improvement of existing product
• Redesign of some features of an existing product
  due to
• Customers request no longer supply of materials
  or components from the vendor needed improvement
  in manufacturing or New technology or new
  understanding of an existing technology
• Development of a new product for a single (or
  small) run or for mass production
• Members of the Design Team
• Product design engineer
• Product manager (product marketing engineer)
• Manufacturing engineer Detailer Drafter
  Technician Materials specialist QC/QA
  specialist Analyst Industrial engineer
  Assembly manager Vendors or suppliers
  representatives
• Structure of Design Teams
• Functional Organization (13 )
• Each project is assigned to a relevant functional
  area, focusing a single discipline
• Functional Matrix (26 )
• project manager with limited authority is
  designated to coordinate the project across
  different functional areas
• Balanced Matrix (16 )
• A project manager is assigned to oversee the
  project and shares the responsibility and
  authority with functional managers.
• Project Matrix (28 )

45
Planning for Deliverables

• Deliverables
• All models of the product, such as drawings,
  prototypes, bills of materials, analysis results,
  test results, and other representations of the
  information generated in the project
• Measure of the progress in design project
• Models vs. Prototypes
• Models are analytical and/or physical
  representations of design information.
• Prototypes are physical models. Solid models in
  CAD can replace the physical models these days.
• 4 Purposes of Prototypes
• Proof-of-concept
• Developing function of the product to compare
  with the goals
• Learning tool
• Proof-of-product
• Refine the components and assemblies
• Geometry, materials and manufacturing processes
  are as important as functions
• Rapid prototyping and CAD models have greatly
  improved the time and cost efficiency in building
  prototypes.
• Proof-of-process
• Verify both the geometry and manufacturing
  process.
• Exact materials and manufacturing processes are
  used to build sample for functional testing.
• Proof-of-production
• Verify the entire production product.

46
Types of Models
An important decision in planning the project
-How many models and prototypes should be
scheduled in the design process? Because of cost
effectiveness, there is a strong move toward
replacing physical prototypes with computer
models. But not always right. Be sure to set
realistic goals for the time required and the
information learned.
47
Five Steps in Planning

• Step 1 Identify the Tasks
• Tasks in terms of the activities that need to be
  performed (generate concepts, producing
  prototypes, etc.)
• Make the tasks as specific as possible.
• Step 2 State the Objective for Each Task
• Each task must be characterized by a clearly
  stated objective
• The results of the tasks (or activities) should
  be the stated objectives.
• Task objectives should be
• Defined as information to be refined or developed
  and communicated to others.
• This information should be contained in
  deliverables
• Easily understood by all in the design team.
• Specific in terms of exactly what information is
  to be developed. If concepts are required, then
  tell how many are sufficient.
• Feasible, given the personnel, equipment, and
  time available
• Step 3 Estimate the Personnel, Time, and Other
  Resources Needed to meet the Objectives
• Step 4 Develop a sequence for the tasks
• Step 5 Estimate the Product Development Costs

48
Step 3 Estimate the Personnel, Time, and Other
Resources Needed to Meet the Objective

• Necessary Identification for each Task
• Who on the design team will be responsible for
  meeting the objectives?
• What percentage of their time will be required?
• Over what period of time they will be needed?
• Time (in hours) A x PC x D0.85
• A a constant based on past projects
• A 30 for a small company with good
  communication
• A 150 for a large company with average
  communication
• PC product complexity based on function
  PC ? j x Fj (j the level in the functional
  diagram Fj the number of functions at that
  level)
• D project difficulty
• D 1, not too difficult D 2, difficult D
  3, extremely difficult
• Time estimation (o 4m p)/6
• O optimistic estimate m most-likely
  estimate p pessimistic estimate
• Time Distribution across the Phases of the Design
  Process
• Project Planning (3 5 ) Specifications
  Definition (10 15) Conceptual Design (15
  35) Product Development (50 70) Product
  Support (5 10)

49
Step 4 Develop a Sequence for the Tasks

• The goal is to have each task accomplished before
  its result is needed and to make use of all of
  the personnel, all of the time.
• For each task, it is essential to identify its
  precessors and successors.
• Tasks are often interdependent two tasks need
  decisions from each other in order to be
  completed.
• Sequential vs. Parallel (uncoupled and coupled)
  tasks
• Bar Chart (or Gantt Chart) best way to develop
  a schedule for a fairly simple project
• Design Structure Matrix (DSM) for a complex
  project with coupled tasks
• Showing the relationship (or inter-dependence)
  among tasks (example see page 104
• Useful tool for to help sequence the tasks (Page
  104)

50
Step 5 Estimate the Product Development Cost

• The planning document can serve as a basis for
  estimating the cost of designing the new product
  in terms of
• Personnel cost
• Resources (supplies and equipment)

• Team Project
• Planning must be done and written in the PDF.
• Read examples in pages from 105 109 for
  planning.
• - Gantt chart or DSM should be good entries.

51
Understanding the Problem and the Development of
Engineering Specifications

• Importance of finding the right problem to be
  solved
• Unnecessary effort to design a retarder
  (dampener) determining the final position of the
  solar panels in the Mariner IV satellite
• Finding the right problem to be solved is often
  not easy although it may seem a simple task.
• Creeping Specifications
• Specifications changing during the design process
• More features can be added as more is learned
  during the process
• New technologies or competitive products
  introduced during the design (ignore, incorporate
  or start all over?)
• Changes in any spec. affecting the previous
  decisions depedent upon that spec
• Engineering Specifications (requirements) should
  be
• Discriminatory
• Reveal the difference between alternatives.
• Measurable (most important and major topic of
  chap 6)
• Orthogonal
• Each specification should identify a unique
  feature of the alternative.
• Product must give smooth ride over rough road.
  vs. Product should reduce shocks from bumps.
• Universal
• Characterizing an important attribute of all the
  proposed alternatives
• External
• Only external features are observable.

52
Quality Function Deployment (QFD)

• Most popular technique used to generate
  engineering specifications in an organized manner
• Developed in Japan in the mid-1970s and
  introduced to the US in the late 1980s
• 69 of the US companys use the QFD method
  recently
• Important Points
• Employ QFD no matter how well the design team
  thinks it understands a problem.
• QFD takes time to complete, but time spent for
  QFD saves time later.
• QFD can be applied to the entire problem and also
  any subproblems.
• QFD helps overcome our cognitive limitation.
• We tend to try to assimilate the customers
  functional requirement (what is to be designed)
  in terms of form (how it will look).

53
Quality Function Deployment (QFD)
House of Quality
54
Example of QFD
Step 1 identify the customers Step 2 determine
the requirements Step 3 determine the relative
importance of requirements Step
4 identify and evaluate the
competition Step 5 generate engineering
specification Step 6 Relate customers
requirements to engineering
specifications Step 7 Set engineering
targets Step 8 identify the relationships
between engineering requirements
55
QFD Step 1 Identify the Customers Who are they?

• For general products
• Who are the customers?
• Consumers
• Designers management
• Manufacturing personnel
• Sales staff
• Service personnel
• Standard organizations
• Etc.
• For many products,
• there are 5 or more classes of customers whose
  voices need to be heard

• For a spinal implant system
• Who are the customers?
• Orthopaedic surgeons
• Neurosurgeons
• Nurses
• Hospitals
• Distributors
• Sales Reps
• Patients ?

56
QFD Step 2 Determine the Customers
Requirements What do the customers want

• Consumers
• works as it should,
• lasts long,
• is easy to maintain,
• looks attractive,
• incorporates the latest technology,
• and has many features.
• Production Customer
• - is easy to produce (both manufacture and
  assemble),
• - uses available resources (human skills,
  equipment, and raw materials),
• - uses standard parts and methods,
• - uses existing facilities,
• - produces a minimum scraps and rejected parts.
• Marketing/Sales Customer
• - easy to package, store, and transport,
• - attractive and suitable for display

57
QFD Step 2 Determine the Customers
Requirements What do the customers want?

• How to collect customers requirements
• Observation of customers
• Surveys mail, telephone, face-to-face
• Focus-group technique
• A group of surgeons for orthopaedic implants
• Steps for developing useful data for
  requirements
• Specify the information needed
• Reduce the problem to a single statement. If
  impossible, more than one data collecting effort
  may be warranted.
• Determine the type of data-collection method to
  be used
• Depending on the use of data collection methods
• Determine the content of individual questions
• Write a clear goal for the results expected from
  each question.
• Design the questions
• Each question should seek unbiased, unambiguous,
  clear and brief information.
• Do not assume that the customers have more than
  common knowledge use jargon lead the customer
  toward the answer you want tangle two questions
  together.
• Do use complete sentences
• Order the questions
• Order them to give context

58
QFD Step 2 Determine the Customers
Requirements What do the customers want?

• Types of Customers Requirements
• Functional Performance
• Performance about the products desired behavior
• Flow of energy, information, or materials
  Operational steps operation sequence
• Human Factors
• Required in any products that is seen, touched,
  heard, tasted, smelled or controlled by a human
• Appearance Force and motion control Ease of
  controlling and sensing state
• Physical Requirements
• Available spatial envelope Physical properties
• Reliability
• Mean time between failures Safety (hazard
  assessment)
• Life-Cycle-Concerns
• Distribution (shipping) Maintainability
  Diagnosability Repairability Testability
  Cleanability Installability Retirement
• Resources Concerns
• Time Cost Capital Unit Equipment Standards
  Environment
• Manufacturing Requirements
• Materials Quantity Company capabilities
• For Spinal Implants

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Resource Concerns

• Time requirements
• Timing to introduce a new product
• Cost Requirements
• Capital Cost
• Cost per Unit
• Cost estimation will be covered in Chap 12.
• Standards (Codes)
• Types of Standards
• Performance seat-belt strength, helmet
  durability
• The Product Standards Index lists US standards
  that apply to various products.
• American National Standards Institute (ANSI) does
  not write standards but is a clearing house for
  standards written by other organizations
• Test Methods
• American Society for Testing and Materials (ASTM)
  publishes over 4000 individual standards covering
  the properties of materials, specifying equipment
  test the properties and outlining the procedures
  for testing.
• Underwriters Laboratories (UL) testing standards.
  
• Codes of Practice
• Give parameterized design methods for standard
  mechanical components, such as pressure vessels,
  welds, elevators, piping and heat exchangers
• Knowledge of which standards apply to the current
  situation are important to requirements and must
  be noted from the beginning of the project
• Environment Concerns

60
QFD Step 3 Determine the Relative Importance of
the Requirements Who vs. What

• Evaluate the importance of each of the customers
  requirements
• Generate a weighting factor for each requirement
  considering
• To whom is th