Senior Design Exam 2

Concept Development Process

The early design phase where customer needs are translated into engineering requirements, initial concepts are generated, evaluated, and refined into a coherent product direction.

System-Level Design

The stage where the overall product architecture is defined, subsystems and interfaces are laid out, and concept variants are organized into a full product layout.

Function (in design)

What the product or component must do, expressed independently of how it does it (form-independent).

Form (in design)

The physical embodiment or specific solution that realizes a function (e.g., bolt, spring, linkage, motor).

“What, not How” principle

Functional models should describe what needs to happen (functions) rather than how it is implemented (specific solutions).

Verb–Noun Function Statement

A standardized way to express functions using an action and an object (e.g., “store energy,” “transmit force”).

Function Tree

A hierarchical diagram showing the overall function decomposed into subfunctions that support it.

Overall (Black-Box) Function

The highest-level function of a product with defined inputs and outputs but no internal details.

Subfunction

A smaller, more specific function that contributes to achieving a higher-level function.

Orphaned Subfunction

A subfunction that is not linked to any higher-level function, indicating an error in the function tree.

Alternate Decomposition by User Actions

A decomposition method where the system is broken down by sequences of user interactions instead of functions.

Subtract-and-Operate Procedure

A method where one component is removed, the system is operated without it, and the missing function is identified.

Design Fixation

A cognitive bias where exposure to example solutions limits creativity and leads designers to copy features unconsciously.

Incubation Effect

Creative improvement that occurs when taking a break from conscious problem solving leads to more and better ideas.

Goal of Concept Generation Methods

To increase the quantity, variety, and creativity of ideas while reducing fixation on initial solutions.

Rules of Concept Generation

Include reviewing the problem, suspending judgment, encouraging quantity, building on others’ ideas, and welcoming wild ideas.

Brainstorming

A group-based, judgment-free idea generation technique focused on rapid creation of many diverse ideas.

Mind Map

A visual diagram connecting brainstormed ideas around a central problem, showing clusters and relationships.

Brainwriting Methods

Group ideation methods (6-3-5, C-Sketch, Gallery) that rely on written/sketched ideas passed among participants to avoid dominance and encourage equal contribution.

6–3–5 Method

An ideation method where 6 people generate 3 ideas over 5 rounds, building silently on each other's concepts.

Gallery Method

Individuals generate concepts, post them on the wall, review them as a group, then refine ideas based on feedback.

C-Sketch

A collaborative sketching technique where each participant works on one sketch at a time and passes it along for modification.

Fluency

The total number of distinct ideas generated in a concept generation session.

Originality

The novelty or uniqueness of ideas compared to typical or common solutions.

Variety

The diversity of idea categories or approaches represented in a set of concepts.

Quality

How well an idea is expected to satisfy functional requirements, constraints, and performance targets.

SCAMPER

A checklist (Substitute, Combine, Adapt, Magnify/Minify, Put to other uses, Eliminate/Elaborate, Rearrange/Reverse) to stimulate new ideas.

Directed Concept Generation

Systematic ideation approaches that use known information, physical principles, catalogs, or TRIZ to generate solutions.

Design Catalogs

Collections of known solutions or analogous products used to inspire or inform new design ideas.

Design-by-Analogy

Applying ideas or mechanisms from one domain (e.g., biology, existing products) to solve a design problem in another.

TRIZ

A structured innovation method using contradiction matrices and inventive principles to resolve design conflicts.

TRIZ Step 1 – Identify Design Conflict

Find a pair of parameters where improving one harms the other.

TRIZ Step 2 – Translate Parameters

Convert the conflicting parameters to generalized engineering parameters used in the TRIZ matrix.

TRIZ Step 3 – Use Contradiction Matrix

Look up recommended inventive principles for solving the conflict without worsening the opposing parameter.

TRIZ Step 4 – Apply Principles

Use the identified inventive principles to create new, conflict-resolving design ideas.

Morphological Matrix

A table listing subfunctions with alternative solution options used to systematically generate complete concept variants.

Concept Variant

A complete product concept created by selecting one solution principle for each subfunction in the morph matrix.

Highly Coupled Subfunctions

Subfunctions that strongly affect each other and should be considered together when generating solution options.

Order-of-Magnitude Estimation

A quick feasibility check using rough calculations to compare system performance or viability.

Prototype

An approximation of a product used to test, refine, and validate/verify the design.

Virtual Prototype

A digital model (CAD, FEA, simulation) used to analyze and improve design performance.

Physical Prototype

A tangible model used to test functionality, usability, or performance.

Low-Fidelity Prototype

A quick, inexpensive prototype used mainly to validate customer needs and early usability (“Am I building the right product?”).

Proof-of-Concept Prototype

A prototype focusing on validating function and meeting engineering specifications (“Am I building the product right?”).

Validation

Testing whether the design meets user needs and aligns with intended use cases.

Verification

Testing whether the design meets engineering requirements and performance specifications.

Concept Selection

The process of comparing feasible concepts against criteria derived from needs and specs to choose which concept to pursue.

Pugh Chart

A decision-matrix tool that compares concepts to a datum using +, 0, and – ratings across evaluation criteria.

Datum (Pugh Chart)

The baseline concept used for comparison; receives neutral scores across all criteria.

Risk Assessment Matrix

A qualitative tool combining probability and severity to categorize risks as Low, Moderate, High, or Extreme.

Risk Probability Categories

Levels describing the likelihood of occurrence: Rare, Unlikely, Possible, Likely, Certain.

Risk Severity Categories

Consequences of failure: Negligible, Marginal, Critical, Catastrophic.

Low Risk

Risks that generally pose no significant issues and may only require minor improvements.

Moderate Risk

Risks that need planned management but not immediate intervention.

High Risk

Risks requiring quick action or redesign to prevent them from hindering progress.

Extreme Risk

Critical risks requiring immediate action to eliminate or significantly reduce them.

Hierarchy of Risk Controls

Ranked from most effective to least: elimination/substitution, engineering controls, administrative controls, PPE.

FMEA

A quantitative method of analyzing failure modes

Failure Mode

The specific way a component or subsystem might fail (fracture

Failure Effect

The impact of a failure mode on system performance

Failure Cause

The underlying mechanism leading to failure such as fatigue

Severity (S)

A 1–10 rating describing how serious the consequence of a failure is

Occurrence (O)

A 1–10 rating describing how likely a given failure cause is to occur

Detection (D)

A 1–10 rating describing how likely it is to detect a failure before it reaches the user

Risk Priority Number (RPN)

A numeric risk score calculated as Severity × Occurrence × Detection used to prioritize actions

Design for X (DfX)

A design philosophy optimizing a product for a specific target such as cost

Design for Manufacturing (DfM)

Designing components to be easy

Design for Assembly (DfA)

Designing to simplify and speed up assembly by minimizing fasteners and making parts easy to orient

DfMA

Combined DfM and DfA principles used to reduce part count

KISS Principle

A guideline emphasizing simplicity to reduce cost and improve reliability (“Keep It Simple

Theoretical Minimum Number of Parts

A rule stating a part should only exist separately if required for motion

Minimize Parts Heuristic

Combining features into fewer parts to reduce assembly time

Easy Insertion Heuristic

Designing parts with guiding features to ensure they naturally orient and assemble correctly

Minimize Fasteners Heuristic

Favoring integrated fastening features like snap-fits instead of screws or bolts

Design for Additive Manufacturing (DfAM)

Applying design rules optimized for 3D printing

AM Benefit: Complexity Independent of Cost

Additive processes allow complex shapes and internal channels with little added cost

Overhang Rule (45° Rule)

Overhangs steeper than ~45° typically require support material during printing

Accessible Support

A DfAM rule stating all supports must be reachable for removal or the design must be changed

Minimum Feature Size

A guideline that features should typically be ≥1.0 mm (printer-dependent) to ensure successful printing

Infill

The internal density of a printed object that controls strength

Part Orientation – Support Minimization

Orienting a part to reduce overhangs and minimize required support structures

Part Orientation – Surface Finish

Orienting a part to reduce stair-stepping and improve finish on critical surfaces

Part Orientation – Load Direction

Aligning print layers so that material strength is maximized along expected load paths