Efficient Engineering teams fully specify before they design !! 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 (End User Testing) Product & Block Level>>>Verification (Bench Testing) Efficient Engineering teams fully specify before they design !!

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

Requirements Imply Proof of Satisfaction 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

Design Blocks Complex products require that the design be broken into logical design elements (termed blocks in this course) 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

Design Blocks Logical Design Partition Elements Mandatory Rules About Design Blocks: Design Blocks Must Cover 100% of Product Assembly All Design Blocks Must have an Assigned Team Member (Owner) Min 1 Design Block is Assigned to Each Team Member Design Blocks May NOT be Jointly Assigned/Owned Team Members May be Assigned More Than 1 Design Block Min of 5 Elec Components Must be formally Specified by each Team Member and May Spread Across more than 1 Design Block This includes all R’s, C’s, L’s, Sockets, Connectors, Cables, Displays, Relays, Switches, etc Blocks form the basis of standardized design elements that are evaluated in this course

Allocation and Association to Design Blocks ALL Product 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 ….

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

Choose & Understand your Market “before” …………. you design a product System - Std Reqs: Market & Business Case Requirement Units to Specify Competitors Market Size Average List Price Market Geography Market Demography Intended Application Material Cost Manufacturing Cost Annual Volume 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 # of units/yr Choose & Understand your Market “before” …………. you design a product

Consider Simultaneous Min or Max Cases Some will NOT be “testable” System - Std Reqs: Env & Safety Requirement Units to Specify 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 Co Range Rh% Range Meters or ATM, Range Time in Days or Years List of IEC or FCC stds List UL, IEC or other stds Consider Simultaneous Min or Max Cases Some will NOT be “testable”

System - Std Reqs: Power Input(s) Requirement Units 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 Must consider power source(s) early Undefined DC power sources NOT allowed

Package and Mechanical Design Impact Many Product Aspects System - Std Reqs: Mechanical Requirement Units to Specify Max Volume Max Ship Container Size Max Mass Elec I/F Connector(s) Max # of PC Bds Max PCB Circuit Area Max Shock 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) Package and Mechanical Design Impact Many Product Aspects

System - Std Reqs: Mfg & Life Cycle Requirement Units to Specify 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 # Total Parts incl elec & mech # of Unique Parts $ (Parts+Mfg=Product Cost) Time = MTBF(yrs) Time (yrs) Return, Recycle, Dispose, etc Dispose or Repair, Factory or Field Product designs should consider full “life cycle” from Mfg process to Disposal

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

Example Requirement Definition System Perf Reqs: Functions & Capabilities Example Requirement Definition Accuracy, Resolution, Frequency of Update, Range Inputs & Output Capability Ex. RF: Distance, Sensitivity Ex. Serial Link: Speed Speed, Accel, Torque, Directions, Cycles, etc. Examples: Laser Sight Alignment SSB & BFO Operation 650Mbyte Capacity Gauge, Measurement of Some Physical Quantity Basic Elec Capabilities Basic Mech Capabilities Basic Functions/Capabilities

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

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

There may be others to Add System – Perf Reqs: Electrical Functions (Must be Defined if Applicable) Requirement Definition 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 There may be others to Add

Every Signal Needs to be Defined in Detail System – Perf Reqs: Electrical Interfaces (For each signal “grouping”) Electrical Signal Req Definition Signal Type Signal Direction Standard Definition Basic Analog Characteristics Detailed Analog Characteristics 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 Every Signal Needs to be Defined in Detail

CANNOT use “TTL” or “CMOS” as Definition System – Perf Reqs: Electrical Interfaces (For each signal “grouping”) Electrical Signal Req Definition Digital Input Type Digital Output Type Basic Digital Characteristics Detailed Digital Characteristics 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 CANNOT use “TTL” or “CMOS” as Definition

All Applicable Must Be Defined System – Perf Reqs: Operator I/F Outputs (Must be Considered if Applicable) Requirement Definition Optical Indicators, Lights Display Type Display Char Matrix Display Size Display Illumination Screen Type Screen Min X Resolution Screen Min Y Resolution Mechanical Indicators 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 All Applicable Must Be Defined

All Applicable Must Be Defined System – Perf Reqs: Operator I/F Inputs (Must be Considered if Applicable) Requirement Definition Switch Type Keypad Type Keypad Matrix Keypad Size Key Definitions Keyboard Type Keyboard I/F Keyboard Total keys Analog Dials 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 All Applicable Must Be Defined

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

Compare Your Possible Projects Project Recommendation Reqs 3 Possible Proj Brain Storm Ideas 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

Compare Your Possible Projects Project Recommendation Reqs 3 Possible Proj Brain Storm Ideas 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?

Compare Your Possible Projects Project Recommendation Reqs 3 Possible Proj Brain Storm Ideas 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?

Excel Requirement Flowdown Template Project Requirements Management Tool Prerequisites For Use: Team is assigned, Project is Selected by Team Decision Product Block diagram is finalized (# of blocks, ownership, interfaces, etc) Most Product Level Requirements have been proposed, discussed, agreed to Spreadsheet Supports up to 10 Total Blocks (can be modified for more) Data Is Entered In the Std and Perf Req sheets (1st two sheets) ONLY Data Is Entered into Beige Shaded Blocks Only ! DO NOT enter data into the Block Spreadsheets Block”n” sheets Xfer ALL info, titles, etc from Std and Perf Req sheets Linkages are Built In for Block levels down to the Block-Block section

Excel Requirement Flowdown Template Each Team Should Customize Template as Needed Number of Design Blocks Hide Columns if Unused, Fewer Blocks Delete Extra Block Sheets Be careful NOT to break Block linkages back to Standard and Perf Reqs Sheets Add specific-unique Block Requirements in the Block-Block sections (next lab)

Excel Requirement Flowdown Template: Product Level - Standard Categories: Market, Power, Mechanical, Environmental, Safety, Manufacturing, & Life Cycle

Excel Requirement Flowdown Template: Product Level - Standard Quantified Requirements, Min, Max Enter Number in Beige Shaded cells Green Cells Autocalculate

Excel Requirement Flowdown Template: Product Level - Standard Unquantifiable Requirements May also have Suggested Lists Enter (Text) Countries, Names, Types, Styles, Stds, etc in Beige shaded cells

Excel Requirement Flowdown Template: Product Level - Standard For Allocations: Enter #% for each block Total % Allocated in listed at right 1 Block May be Assigned as “Margin” and allocated a reasonable % of total OR … Total % Used May be less than 100%

Excel Requirement Flowdown Template: Product Level - Standard For Associations: Enter “XX” for each block that is associated with the product level requirements The XX will transfer to each block sheet.

Excel Requirement Flowdown Template: Product Level - Performance Categories: User Inputs User Indicators & Displays Operation Modes Electrical Interfaces Electrical Performances Mechanical Interfaces Safety Caution: Perf Requirements Listed May NOT be applicable to your project Use only those necessary Add additional as necessary but be careful not to break links

Excel Requirement Flowdown Template: Product Level - Performance Most Requirements are Quantifiable: Min, Max Must be Entered as Defined Enter Numbers in Beige Shaded cells

Excel Requirement Flowdown Template: Product Level - Performance Unquantifiable Requirements have Suggested Lists Enter (Text) in Beige shaded cells

Excel Requirement Flowdown Template: Product Level - Performance Same Scheme for Allocation and Association Caution: Not ALL quantifiable requirements will allocate, you may need to fall back on just association

Excel Requirement Flowdown Template: Product Level - Performance Product Level Electrical and Mechanical Interfaces shown here will transfer to blocks to which they are contained in. (but they must be associated correctly)

Excel Requirement Flowdown Template Example of Block Output from Tool

Block-Block Interfaces: Must be customized to each block Categories: Digital Signal Inputs Digital Signal Outputs Analog Signal Inputs Analog Signal Outputs Power Inputs Power Outputs Electrical Transfer Functions Mechanical (Connectors) Caution: Block Unique: Requirements Listed May NOT be applicable to your project Use only those necessary Add additional as necessary but be careful not to break links