Design process is a collection of procedures and habits that help teams design better products.
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Transcript of Design process is a collection of procedures and habits that help teams design better products.
Design process is a collection of procedures and habits that help teams design better products
Designing is the process of making many decisions that converts a need into a hardware reality.
Need Product
1. Product Design Specifications (PDS)2. External Search (Research) 3. Internal Search (Brainstorming)4. Concept Evaluation and Selection5. Detail Design (Engineering) 6. Prototyping and Testing7. Documentation
Step Outcome
Product Design Specifications PDS Document
External Search (Research) List of existing related products and technologies
Internal Search (Brainstorming)
A lot of solution ideas
Concept Evaluation / Selection Pros and Cons / Decision MatrixSelection of one idea to implement
Detail Design (Engineering) Determination of all details needed to build the product
Prototyping and Testing Comparisons to PDS targetImprovement recommendations
Documentation Final Design ReportBOM + Production DrawingsAll other reports
Rope Climber
Can CrusherCoin Sorter Better Mouse Trap
Water Balloon
Nail Driver
Rope Climber
Climbs fast Affordable as a birthday present Fully assembled Uses batteries for power No small parts – is safe Looks good Plays music as it climbs Glows in the dark Lasts a long time Would not violate any patents
START
Expensive
Patents BatteryLifeSlow
Unsafe
No Glow
Silent
Indoors Only
Desired Boundary Retail < $45
Acceptable BoundaryRetail < $50
High PriorityPlays Music
Low PriorityGlow in the dark
Cannot be taken apart Has no small parts or sharp edges Only to be used indoors It is light and compact Does not use toxic materials Fits into a small box for shipping Has attractive packaging Design and testing finished in 4 months Quantity 1 Million
Climbs at 1 ft/s or faster Retail cost is to be less than $45 Uses 2 AA batteries Has 0 removable small parts Music loudness between 20-30 db Luminosity is to be more than 5 C Works for minimum 3 hours on 2 AA
Level-I◦Rope climbing toys / machines◦Rope climbers (sports or circus)◦Nature (spiders, bats, etc)
Level-II (friction wheels selected) Hoists Trolleys Ski Lifts
Brainstorming◦Generate many ideas◦Evaluate against PDS◦Evaluate risks◦Select one to engineer
Lift and Drag Coefficients (as effected by ground promimity)
0
0.050.1
0.150.2
0.250.3
0.35
0 0.05 0.1 0.15
h/L
Co
eff
icie
nt
Drag Coefficient
Lift Coefficient
More Abstract Engineering Less Abstract
Applies to Top-level decisions Applies to lower levels decisions
◦ Define requirements◦ Search for existing ideas/technologies◦ Brainstorm for solutions◦ Pick a candidate◦ Determine the details
Concept Synthesis
PDS
Concept Evaluation
Candidate Design
Detail Design
Candidate Design
Release for Production
Prototyping
Parameter Design
Candidate Design
Release for Production
System-Level Design
Prototype Testing
Components
No Numbers
Numbers
Complexities of Developing a PDS Document
• Level-I: – Goal is clear, “Design a X to do Y”– specifications are known, – priorities are known, – no mass production concerns, – IP issues not important, – limited customer base – Example: one-of-a-kind equipment.
Complexities of Developing a PDS Document
• Level-II: – Goal is specific “Design a X to do Y”, – Specifications are unknown, – Priorities are unknown, – Mass production concerns, – IP issues are important, – expanded customer base – Example: Most consumer products
Complexities of Developing a PDS Document
• Level-III: – Goal is unclear, “Design ? To do ?– There is a general statement of need– Not easy to get to: “Design X to do
Y” – Example: Oceans are rising
People who define the PDS People who influence product success People you cannot ignore
Team
Company
(Internal)
Globe
(External)
A successful product:1) Sells well and makes a lot of profit2) Would not violate any laws/regulations
What about:◦ Safer than law requires?◦ Solves some problems of humanity?◦ Is green (energy efficient, recycles, etc)?◦ Lasts more than warranty period?◦ Perform better than required?
Only when they relate to 1) or 2)
Customers The design team and its members are not customers Every PDS statement must be associated with at least one customer Internal customers are within the organization (management,
marketing) External customers are outside the organization(end users)
EXTERNAL
End Users
Maintenance
Society(Marketing)
Retailer
Company Buyers
Government &
Standards
InternalMarketing
Legal
Manufacturing &
Procurement
Management
ShippingPackaging
What Do They Want?• End users want
– Performance & Functionality– Affordability– Ease of use including ergonomics– Reliability and Long life– Robustness– Versatility– Safety– Low maintenance and easy assembly– Esthetics
External Customers• Buying managers want
– Low Cost/Performance– Safety– Ruggedness (abuse resistance)– Ergonomics– Long warrantees– Reliable with Low downtime– Low operating cost
External Customers• Retailers want
– Small and attractive packaging– Long shelf life– Low cost high profit – Exciting features
• Maintenance wants– Ease of maintenance– Low cost of maintenance
External Customers• Government wants
– Conformance to laws and regulations
• Standards want– Conformance to industry standards– Conformance to codes
Internal Customers• Management wants
– Make $$$– On time delivery– Low risk of financial failure– Proper Documentation– Process: Conformance to company
product development process
Internal Customers• Marketing wants
– Attractive features to target buyers– Low retail price– Esthetics– Attractive packaging– Ease of user assembly/maintenance– On time delivery– Long Warrantees
Internal Customers• Manufacturing / Purchasing want
– Available materials– Manufacture-able at low cost.– Conformance to company
documentation formats.– Use of products from preferred
vendors.
Internal Customers• Legal wants
– No patent infringements– Safety
• All required safety warnings and labels• Protection against reasonable abuse• Safety manual
– Conformance to laws and regulations
Internal Customers• Shipping and Packaging
– Small (standard) package sizes– Ability of locking or fixing sensitive
components– Resistance against damage due to
dropping, vibrations, moisture, heat, and cold.
Product Design Specification
• Is this a PDS item?– Is there a customer associated with it?– Does the information limit the design
selections and choices?– Can the requirement be designed into
the product?• High resale value• Win the Noble Prize
Product Design Specification
• Elements of PDS– Performance (Primary customer: End User)
• Speed, • Capacity, • Power, • Efficiency,• Accuracy, • Return on investment• etc.
Elements of PDS– Environment: (User)
• Temperature range, rain, humidity, dust.
– Life in service: (User)• 10 years, 5000 cycles, etc.
– Maintenance: (User)
• The market policy, what customers accept
– Retail/Production cost: (User)
• Consistent with comparable products• Rule of thumb 4:1
Elements of PDS• Shipping/packaging:
– Package sizes + Weights– Damage resistance
Elements of PDS• Quantity (Marketing)
– Determined by marketing
• Manufacturing facility (Management)
– Does the company policy dictate certain facilities?
Element of PDS• Size and shape (Marketing)
• Weight (Marketing)
– What is the desired weight?– Handles for lifting points?– Modular?
• Aesthetics (Marketing)
– Color, shape, form, texture, finish.– Market research.
Elements of PDS
• Materials (Marketing, Codes, Regulations)
– Left to designers unless company guidelines or regulations restrict certain materials (asbestos, lead).
• Product life span (Marketing)
– Designed life
Elements of PDS
• Laws, Codes, and standards (Government)
• Ergonomics (User + Marketing + buyers)
Elements of PDS• Quality and reliability (Marketing)
– Company policy regarding warranties– Failure rate during warrantee period
• Testing (Marketing)
– Tests to perform to verify performance and other PDS requirements
– Industry standard tests
Elements of PDS• Shelf life (storage) - Retail
– Possibility of rust, decay, deterioration
• Processes (Mangement)
– Conformance to certain standards (GD&T or ISO 9000 for example)
– Use of company procedures
• Time-scales (deadlines) - Management
– Whole design project, milestones
Elements of PDS• Safety (User, Government, Legal)
– Safety requirements mandated by government
– Professional society's codes and standards
– Need for warning labels– Design against Acceptable degrees of
abuse
Elements of PDS• Company constraints (Management)
– Compatibility with other products
• Documentation (Management – Legal)
– Full documentation (Guard against possible litigation)
– Safety, Operation, and Service documents.
Elements of PDS• Legal (Lawyers)
– Product liability law suits associated with similar products and why.
– Relevant patents
Element of PDS• Installation (Installers)
– Connection geometry. – Various models to install
• Disposal (Marketing)
– Recyclable?– bio-degradable?– Green
Other Element of PDS• Other possible PDS items to include
– Rugged– Easy to use– Reliable– Quiet– Portable– Source of energy
Before you Interview Sponsors
• Prepare your questions (PDS)• Let them do most of the talking• Take notes• Ask for clarification• Do not be annoying (you can always ask
more questions later if deemed important)
Wording of the PDS Document
• Format of most statements in PDS:– The device must ……..– The device is to ……– The device is desired to ….
• Avoid mixing requirements. – One sentence per requirement.
• Cast PDS statements in a positive format
PDS is a Dynamic Document
• A design statement usually begins as a vague statement– The device is to be easy to use– The device is to be safe– The device is to be inexpensive– The device is to be rugged and reliable– The device is to be portable
Wording of the PDS Document
• Example: ESCO’s Pin Remover– The pin-remover is to be light.– The pin-remover must work in a wet,
cold, and dusty environment.– The Pin-remover must be safe – The Pin-remover must have a 3-year
warranty.
PDS Example• The Pin Remover is to be rugged.• must work with air pressure.• is to be easy to use.• is to pass “ASME standard” tests.• is to last 5 years in normal usage.• is to be easy to carry.
PDS Example• is to sell for less than $150.• is to cost less than $50 to make. • is to have low maintenance needs. • is to be difficult to use as a hammer.• must not infringe patented devices. • Production volume is 3000 per year
PDS Example• is to be tested by June 2013. • is to be released by Sep. 2013.• is to be usable with all Dredge
models.
• is to work faster than a hammer
Engineering Specifications
• Engineers cannot design for vague criteria– “Fast, accurate, high-performing”– “Light, Small, portable”– “Easy to use”– “Safe”– “Stylish” (maybe)
Engineering Specifications
– Verifiable PDS statements– Developed for important PDS
statements– Have associated target numbers
•BUT– Do not push the customer for numbers
A Typical PDS Page
• Requirement: PR is to be easy to maintain– Primary customer: End users– Priority: High– Metrics and Targets
• Daily maintenance: None• Weekly maintenance: < 10 minutes – field• Yearly maintenance: < 1 hour – Shop• Cost of weekly maintenance < 10c• Cost of yearly maintenance < $10
Methods of setting targets
Some targets are specified by:• Marketing• Management• Regulations /standards• Users / buyers / retailers• etc
Methods of setting targets
• Benchmarking + parametric Studies• Technology capability• Field experts• Experimentation• Educated guesses• Select ranges for targets from Barely
acceptable to highly desirable
HoQ
Customer Needs
PDS
Statements
Engineering Requirements Competition
IMPORTANCE
Competition
Relation Between Engineering and Customer Needs
Target