1. Penn Fall 2013 -- DeHon Senior Design Skills and Advice September 27, 2013 Specification and Concept Generation

2. Message Don’t Panic –about solving everything at once –Employ wishful thinking Don’t get stuck on first idea –Generate many –Mix & Match –Get Systematic Evaluate ideas against constraints and priorities Penn Fall 2013 -- DeHon

3. Senior Design Intro Penn Fall 2013 -- DeHon

4. Engineering Design Methodology Problem Definition Requirement Ident. and Analysis –Priorities Specification Problem Decomp. Concept Generation –Brainstorming Modeling Parameterization and Design-Space Exploration Benchmarking Concept Selection Prototyping Implementation Testing Debugging Evaluation

5. Engineering Design Methodology Problem Definition Requirement Ident. and Analysis –Priorities Specification Problem Decomp. Concept Generation –Brainstorming Modeling Parameterization and Design-Space Exploration Benchmarking Concept Selection Prototyping Implementation Testing Debugging Evaluation

6. Penn Fall 2013 -- DeHon Specification Before can start solving –Need to know what your solving Before can evaluate “goodness” –Need to know what trying to accomplish –Priorities

7. Penn Fall 2013 -- DeHon Quantitative Specification Typically need to –turn vague specification –into something quantifiable/measurable Something concrete From: fast packet processing –To: process 700B packets at Gb/s – added latency of 15 microseconds

8. Penn Fall 2013 -- DeHon Specifications More of a trick/challenge for things that don’t have natural metrics –From: Door closes easily –To: Door latches with <5 lbs. Of force… –From: reliable –To: 1 failure in 10 9 hours of operation 1 undetected failure …

9. Penn Fall 2013 -- DeHon Establish Priorities Which requirement is king? Which have flexibility? –Can tradeoff? Ex: Requirements – quad rotor –Cost in Volume (<$200) –Battery Life (>15 minutes of flying) –Payload (up to 1 kg)

10. Penn Fall 2013 -- DeHon Establish Targets Acceptable Ranges Ideal Usually Relative to alternatives/competitors Problem formulation should capture priorities

11. Penn Fall 2013 -- DeHon RotoRouter Targets and Priorities Starting Point –Support TCP/IP –Operate with Introduction Based Routing –Logic fit in NetFPGA (gates, memory) Cryptographic hardware couldn’t be too large –Run at Gb/s line rate Cryptographic hardware must be fast –Detect and limit “bad” traffic Less than 10% impact on “good” traffic –Prevent tampering with packets

12. Penn Fall 2013 -- DeHon Concept Generation

13. Penn Fall 2013 -- DeHon Goal of Concept Generation Fully explore design space –Not miss options –Open minds to possibilities –Know what we can do Competitors can do

14. Penn Fall 2013 -- DeHon Components Structured Approach Partial Solutions Uncertainty/Unknown Documentation

15. Penn Fall 2013 -- DeHon Non-Atomic Insight Nothing will ever be attempted, if all possible objections must be first overcome. --- Samuel Johnson, 1759.

16. Penn Fall 2013 -- DeHon Uncertainty “Do you remember what I have taught you? Most intelligent beings prefer to live in certainty than uncertainty. Rather than accept uncertainty, they will discount the input of their own senses. It is through this mechanism that mages manipulate the perception of others.” --- Elric to Galen upon his [Elric's] death Invoking the Darkness, Jeanne Cavelos

17. Penn Fall 2013 -- DeHon Concept Generation: Steps Start refined problem specification 1.Clarify/decompose 2.Search –Externally –Internally / brainstorm 3.Explore Systematically 4.Reflect

18. Penn Fall 2013 -- DeHon Decompose Separate components must solve –Divide and conquer Maybe attack w/ separate passes through process Focus on bottleneck –Critical path/subproblem –Where most risk is Most innovation needed

19. Router Decompose Decide where packet needs to go Switch packet Ensure integrity Ensure privacy Validate packet wanted by destination Penn Fall 2013 -- DeHon

20. Quad Rotor Decompose Propulsion Location – how know where you are Energy supply Control and Stabilize Motion Control Route Planning Payload pickup and hold Penn Fall 2013 -- DeHon

21. Search Externally Literature –Published / library –Web….google, IEEE DL, ACM DL –Patents Customers Experts (faculty/research labs, advisors, industry contacts) Benchmark related / competitive Understand state-of-art

22. Penn Fall 2013 -- DeHon Search Internally/Brainstorm Common bugs: –Reject things too early “Nothing…” quote –Latch onto few ideas Get stuck in own local minima

23. Penn Fall 2013 -- DeHon Search Internally/Brainstorm Different mode of thinking Generate lots of ideas Suspend judgment / no squashing Grow mode / acid mode Find good pieces, incomplete ideas Wishful thinking Comfortable with uncertainty

24. Penn Fall 2013 -- DeHon Brainstorm Throw out ideas Write them down … draw pictures De-personalize –Name by characteristics not person –Not attacking person/idea –Group ownership –Everyone contribute to debugging Friendly amendments Mix-and-match Good science –Find best ideas, avoid Not-Invented-Here syndrome

25. Penn Fall 2013 -- DeHon People and Brainstorming Good to have both individual and group thinking times More brains generally good –Maybe limit size of group at a time –Different perspectives good Group ownership of final product –Involve stake holders –Build confidence in conclusion –Get buy in

26. Penn Fall 2013 -- DeHon Systematic Exploration Parameterized Design Space –Knobs can turn to move between design points? Concept combination matrix Classification tree Goals: –Find holes –Over-emphasis –Make sure think about all cross products…

27. Penn Fall 2013 -- DeHon Reflect Throughout process Comfortable solving problem? –Specification adequate? Process

28. Message Don’t Panic –about solving everything at once –Employ wishful thinking Don’t get stuck on first idea –Generate many –Mix & Match –Get Systematic Evaluate ideas against constraints and priorities Penn Fall 2013 -- DeHon

29. Time Permitting Work on example(s) –Decompose –Brainstorm Penn Fall 2013 -- DeHon