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System Design



Description Link
Human Engineering Design Standard (MIL-STD-1472H) (RCMD) WEB-PDF


Description Links
1968 Golden Globe Race (sail around the world) WEB / HackerNews
Next-Gen UI Examples WEBSITE / HackerNews
Aesthetic Intuition Practice WEBSITE
The Design of Everyday Things (Book, 2013, Don Norman)
The Design of Future Things (Book, 2009, Donald A Norman)
Handbook of Human Factors and Ergonomics (Book, 2021, 5th Edition, Gavriel Salvendy and Waldermar Karwowski)

Key Knowledge

Description Notes

Design is description and desire for how something can and should be. Draw lines and curves (form). Fill with atoms (composition). Symbolize ideas (abstraction). Plan cause-effect possibilities (interactive potential).

Abstract Design

Keyword Description
Design Finality Make design decisions that survive (ideally forever, but at least up to the upcoming/next commercial release)


Absolute Quality Score (X / 5): The general measure of quality of a product or service.

  • 5/5 = one of the best possible designs based on leading-edge technologies with zero false-tradeoffs and zero relevant-errors
  • 4/5 = excellent design with significant optimizations, no major errors or false-tradeoffs
  • 3/5 = good design; no major errors affecting primary requirements, optimized
  • 2/5 = sufficient design; no significant errors, mostly unoptimized, clear unrealized-potential
  • 1/5 = barely functional; significant errors, generally unoptimized, clear unrealized-potential
  • 0/5 = does not meet functional requirements

Incremental Quality Score (X + I): An additive measure of each meaningful improvement on top of the base design as marked by +1 score (ex. +3 for a batch of 3 improvements). The base design is the existing design (for design revisions) OR the simplest possible design (for new designs).

Example: The design of scissors. Consider 2 thin steel blocks with sharpened inner edges and holes, held together by a locknut and bolt (absolute 0/5, incremental X). Add rounded edges and simple finger-slots on the holding-end (1/5, X+2).

Design Direction

Unlimited Possibility Space: The idea of a space where absolutely anything can happen. The greater your imagination, the greater fraction of this space is thinkable.

Available Possibility Space: What is possible in the world within a certain timeframe, from a collective or individual perspective.

Design Goals: The abstract and specific reasons for considering a design space in the first space.

General Branching: Grouping similar design possibilities under a single keyword/concept. Remove bad branches from the design space. Avoid tunnel visioning into a good branch where other good, perhaps better, branches also exist.

False Tradeoffs: Where normally an improvement in A causes a worsening in B, a new approach that allows a pure improvement in A. Ideally discover all false tradeoffs and accordingly apply all pure improvements possible.

Prioritization: Deciding the best design balance of strengths and weaknesses, supported by a deep understanding of the goals, and required by the existence of true tradeoffs.

Specific Completion: Finalizing all design details required to build a prototype or produce at scale with perfect clarity.

Practical Design

Basic 1: Safety, Performance, Reliability, Durability, Longevity

Note: durability means it does not break easily, longevity means it generally works for a long time, reliability means it consistently works (during its specified lifetime, even if non-critical parts break easily). Something can be reliable and fragile/short-lived.

Basic 2: Size, Weight, Form, Noise, Power, Functional Efficiency (input-output)

Lifecycle: Design for... Manufacturing, Transportation, Storage, Assembly, Deployment, Configuration, Customization, Maintenance, Repair, Removal, Recycling

Environment: Design for... Temperature (ex. thermal expansion), Ingress/Submersion (ex. dust/dirt/sand/water), Condensation, Erosion (natural/artificial), Corrosion, Sunlight (ex. UV exposure), Precipitation (avoid standing water, assess drip dynamics for externalities), Pressure (atmospheric/special)

Design Goals:

Description Notes
Single User Operation


Safety Methods: Danger Removal, Danger Reduction, Shielding, Lockout, Signaling, Intuitive Interface (subconsciously guide safe user experience), Instructions

Failure Planning: Self-Test (Start-up, Dynamic), Pre-Failure Signals/Mechanisms, Graceful Failure, Human Error Tolerance, Blackbox Logging (identify root cause, improve next version)

Functional Safety: IEC 61508 (industrial), ISO 26262 (automotive), IEC 60730 (household)


Common Events: Impact Test (random shock), Compression Test (random weight), Drop Test (avoid damage/injury/shatter/chip)

Dynamic Environment: Rolling Stopper (Recovery from Fall on Angled Surface), Relatively-Distinct Color (Lost-and-Found Detection)

Cleaning: Smooth Surfaces, Hand-Fitting Internal Volumes, Compatible with Water Immersion and Spray, Minimal Contact with Floor, Easy-Clean Exterior (non-magnetic, non-adhesive, cleaning-chemical-compatible), Low-Splash Surface, Acceptable-Splash-Angle Surface


Speed: Motion, Data Transmission, Data Processing, Chemical Reaction Rate


Constrained Use: One-Handed Use, Independent Use, Low-Tactile-Sense Use, Color-Blind Use, Impaired Vision Use, Impaired Hearing Use, Long-Distance Use, Awkward-Angle Use

Ergonomic Methods: Rounded Corners and Edges (Comfortable Handling), Handle (Intuitive Carrying), Grab Points (Non-Slip Lifting), Low Thermal Conductivity (Warm Handling), Tactile Feedback (Correct-Input Signal)

Intuitive Sequence: Left-to-Right, Top-to-Bottom


Temperature: operating range, derating, cycling before use, cycling during use, freeze-thaw resistance, flame retardance (UL94)


Signals: Maintenance Reminder, Problem Warning, Maintenance Guiding

Special: Spare Parts Inside Product (Useful Unity), First-to-Fail is Easiest-to-Replace (Zero Maintenance Damage Mitigation), On-Part Info Sticker/Engraving (ex. Company Name, Part Number)


Resistance: Scratch, Chip, Dent, Vibrate, Fatigue, Shock, Ingress (prevention, ) Chemical, Galvanic Corrosion

Size, Weight, Form

Fit Through: Standard Door, Garage Door, Car Door, Spiral Corridor,

Fits Inside: Car Trunk, Car Seat, Backpack, Pocket

Special: Stackable Storage, Stackable Operation, Stands Upright Independently, Table Function (Large Flat Top), Floor Weight (High-Traction, High-Weight), Step-Stool (Small Flat Top, High-Stability)

Mechanical Unity: consistent physical connectivity; ex. car gas-cap is tethered


  • disaster-tolerant design