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Example of User to System Level – Flowdown

Definition: “ Statements of desired product performances and features used to define and quantify a product design” User Level : Special list or labels which state the intended application and/or purpose of the product (Labeling)

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Example of User to System Level – Flowdown

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  1. Definition: “Statements of desired product performances and features used to define and quantify a product design” • User Level: Special list or labels which state the intended application and/or purpose of the product (Labeling) • Product Level: (System Level) Quantitatively state all features, performances, and interfaces in “Eng Terms” • Block Level: State all features, performances and interfaces describing the block in “Engineering Terms” • User Level >>> Validation • Product & Block Level>>>Verification Efficient Engineering teams fully specify before they design !!

  2. Example of User to System Level – Flowdown User Level: “Indoor/Outdoor Operation & Storage” Product or System Level: Max Oper Temp Range: -40C to 55C Max Oper Humidity Range: 0-100% Non condensing Max Oper Altitude Range: -300ft to 15,000 ft above sea level Max Storage Temp Range: -50C to 65C Max Storage Humidity Range: 0-100% Non condensing Max Storage Pressure Range: 0.5 to 1.5ATM

  3. Requirements Imply Proof of Satisfaction !Implied Product Design Integrity ! • Many Gov’t Agencies mandate that ALL product requirements should be user validated and/or engineering verified (tested or justified). A requirement which cannot be verified or validated should not be stated unless objective evidence can be compiled to prove its satisfaction • Requirement Categorization Used in this Course: • Standard: Common to ALL Project Teams • Performance: Unique to Project and Technology, For Differentiating

  4. Design Blocks • Complex products require that the design be broken into logical design elements (termed blocks in this course) • Min 1 Design Block per team member is Mandatory • Blocks form the basis of standardized design elements in this course. • The terms Product and System are used interchangably • Product Level Requirements can either be allocated or just associated to all design blocks. • The Project System Design entails defining ALL Block Performance Reqs incl Interfaces and Functions

  5. Allocation and Associationto Design Blocks • ALLProduct Level Requirements Must be allocated or associated to each Design Block within the project to complete a System Design Phase • Allocated: % of total budgeted to applicable design blocks plus margin. For example: Product Cost, Power Consumption, Mass …. • Associated: Used when allocation is not applicable. For example: Country(s) of Market, Annual Volume, Safety Standards ….

  6. Product Level - Standard Requirements • Standard Requirements are those requirements which are universal and can be applied to nearly all products and hence final projects • Standard Requirements may or may not be differentiating depending upon project goals but MUST be part of the minimum description of the product Standard Reqs Are Common to Nearly ALL Projects

  7. System - Std Reqs: Market & Business Case Choose & Understand your Market “before” …………. you design a product RequirementUnits to Specify • Company Name(s), Model#(s) • Total $/Region, Info Source • $/unit as sold to customers • List of Countries or Regions • Min/Max Age, Sex, Restrictions • Ind, Auto, Home, Wearable, etc • $/unit in volume production • $/unit in volume production • # of units/yr • Competitors • Market Size • Average List Price • Market Geography • Market Demography • Intended Application • Material Cost • Manufacturing Cost • Annual Volume

  8. System - Std Reqs: Env & Safety Consider Simultaneous Min or Max CasesSome will NOT be “testable” RequirementUnits to Specify • CoRange • Rh% Range • Meters or ATM, Range • CoRange • Rh% Range • Meters or ATM, Range • Time in Days or Years • List of IEC or FCC stds • List UL, IEC or other stds • Min Oper Temp Range • Min Oper Humidity Range • Min Oper Alt or Press Range • Min Storage Temp Range • Min Storage Humidity Range • Min Storage Alt or Press Range • Max Storage Duration • Primary EMC Standards • Primary Safety Standards

  9. System - Std Reqs: Power Input(s) Must consider power source(s) early Undefined DC power sources NOT allowed RequirementUnits to Specify • AC, Battery, Photovoltaic, Generator, Fuel Cell, Thermopile etc • Permanent or Temporary • Voltage Range, For each Source • Max Total Watts, For each Source • Watt-Hours/Yr for AC Power, mAHrs for Batteries (Calendar Life Time) • Energy Source List • Source Connection List • Min Oper Voltage Range • Max Power Consumption • Max Energy Consumption

  10. System - Std Reqs: Mechanical Package and Mechanical Design Impact Many Product Aspects RequirementUnits to Specify • Cm3 Total for Entire Product • Cm Max LxWxH for 1 unit • Kilograms • Type & Style (subD, BNC, etc) • Total # • Cm2 Total • G force (Grms), # Reps (depends on environment) • Max Volume • Max Ship Container Size • Max Mass • Elec I/F Connector(s) • Max # of PC Bds • Max PCB Circuit Area • Max Shock

  11. System - Std Reqs: Mfg & Life Cycle Product designs should consider full “life cycle” from Mfg process to Disposal RequirementUnits to Specify • # Total Parts incl elec & mech • # of Unique Parts • $ (Parts+Mfg=Product Cost) • $ (Parts+Mfg=Product Cost) • Time = MTBF(yrs) • Time (yrs) • Return, Recycle, Dispose, etc • Time (yrs) • Dispose or Repair, Factory or Field • Max Parts Count • Max Unique Parts Count • Parts/Mat $ Allocation • Asm/Test $ Allocation • Product Life, Reliability • Full Warranty Period • Product Disposition • Production Life Support • Service Strategy

  12. System -Performance Requirements • Performance Requirements are those requirements which are specific to a product and project • Performance Requirements differentiate the product from all other similar products • Performance Requirements should describe …. • Signal Interfaces • Mechanical Interfaces • Features, Options • Modes of Operation • Performance Parameters • User Controls • User Displays and Outputs

  13. System – Perf Reqs: Power Input(s)(Must be Considered if Applicable) All Applicable Must Be Defined RequirementDefinition • Hz, Range • EFT, Surge, Dropout, etc • Pb-Acid, Li, NMh, Alk, etc • CR2032, C, D, AA, etc • Min mA-Hrs • AC Power Freq Range(s) • AC Power EMC Stds • Battery Chemistry • Battery Std Size • Battery Capacity

  14. System – Perf Reqs: Electrical Functions(Must be Defined if Applicable) There may be others to Add RequirementDefinition • Voltage or Current Gain Ranges • Input – Output SNR • Frequency Response • Linearity and THD • Delay in uSec or mSec • Computation or Algorithm • Compute Speeds in Ops/Sec • Input – Output Delay • Analog Functions • Digital Functions

  15. System – Perf Reqs: Electrical Interfaces(For each signal “grouping”) Every Signal Needs to be Defined in Detail Electrical Signal ReqDefinition • Analog, Digital, or Power • Input, Output, Bidirectional • RS170 Video, RS232, USB, Custom, etc • Voltage Range, Frequency or Bandwidth Range • Impedance or Current Range • Offset Voltages, Currents • Error Voltages, Currents • Max Noise • Other Analog Characteristics • Signal Type • Signal Direction • Standard Definition • Basic Analog Characteristics • Detailed Analog Characteristics

  16. System – Perf Reqs: Electrical Interfaces(For each signal “grouping”) CANNOT use “TTL” or “CMOS” as Definition Electrical Signal ReqDefinition • Std, Schmitt Trigger • Std, TriState, Open Collector • Outputs: Voh, Vol, Ioh, Iol • Inputs: Vih, Vil, Iih, Iil, Vth • Bidirect: Both • Hi Z Leakage Currents • Min Transition Times • Min Setup & Hold Times • Max Frequency • Offset Voltages, Currents • Error Voltages, Currents • Max Noise • Other Analog Characteristics • Digital Input Type • Digital Output Type • Basic Digital Characteristics • Detailed Digital Characteristics

  17. System – Perf Reqs: Operator I/F Outputs(Must be Considered if Applicable) All Applicable Must Be Defined RequirementDefinition • Type, Size, Visibility, Speed, Color, Lumens • 7 Segment, Matrix, LCD • Total Char/Row, Total Rows • Total Size HxW • Daylight LCD, BLLCD, LED, EL, etc • CRT, TFT Panel, • 768, 1024, 1280, etc • 512, 768, 1024, etc • Volume, Pitch, Duration, Vibration, Flags, Other • Optical Indicators, Lights • Display Type • Display Char Matrix • Display Size • Display Illumination • Screen Type • Screen Min X Resolution • Screen Min Y Resolution • Mechanical Indicators

  18. System – Perf Reqs: Operator I/F Inputs(Must be Considered if Applicable) All Applicable Must Be Defined RequirementDefinition • Toggle, Slide, Mom Push, DIP, etc • Matrix or Ind Key Switches • Total Columns, Total Rows • Total Size HxW • Layout, Functions, Labels • QWERTY, QWERTY w/Keypad • USB, IBM 5 Pin, RS232, etc • Number of Keys • Range of Input • Number of Turns • Switch Type • Keypad Type • Keypad Matrix • Keypad Size • Key Definitions • Keyboard Type • Keyboard I/F • Keyboard Total keys • Analog Dials

  19. System – Perf Reqs: Mech Interfaces(Must be Considered if Applicable) Others May Apply RequirementDefinition • Feet, Brackets, Clamps, etc • None, Grips, Bars, etc • Temp, Pressure, Humidity, RPM, Acceleration, Dist, etc • Sub D, IEC-320, USB, etc • Mounting • Carry Handles • Sensory • Connectors

  20. System – Perf Reqs: Modes of Operation(Must be Considered if Applicable) Others May Apply RequirementDefinition • ON/OFF, ON/AC, ON/Battery, etc • Standby, Idle, etc • Program, Configure, etc • Diagnostic, Test, etc • Power Modes • Power Saving Modes • Calibration Modes • Service Modes

  21. Compare Your Possible Projects Project Recommendation Reqs Down Select Your Project Ideas: • Interest: • Does the project hold interest for ALL team members? • Can you identify similar products in the market? • How unique is the project compared to previous capstone projects? • Block Diagram: • Do the project blocks best match the skills and resources available on the team? • Does the block diagram contain at least 1 robust design block for each team member? • Is the block diagram overly complex 3 Possible Proj Brain Storm Ideas

  22. Compare Your Possible Projects Project Recommendation Reqs Down Select Your Project Ideas: • System Perf Requirements: • Can you list the key differentiating performance requirements which would create market demand? • Are you able to quantify the key system performance requirements? • System Std Requirements: • Can you quantify ALL the system standard requirements? • Can you allocate applicable system standard requirements to ALL blocks? 3 Possible Proj Brain Storm Ideas

  23. Compare Your Possible Projects Project Recommendation Reqs Down Select Your Project Ideas: • Prototype and Resources: • How difficult will it be to construct a prototype to demonstrate the primary functionality and performances? • Is the project dependent upon any development tools which may be difficult to procure or gain access to utilize? • Does the prototype depend on key components with lead times that could exceed the project timing requirements such as sensors, displays and transducers? • Does the available financial resource match the estimated cost of the prototype? 3 Possible Proj Brain Storm Ideas

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