Topic 3: Modelling

Conceptual Model

A mental model used to outline the processes and functions of a design or system.

Role of Conceptual Modeling

Brings ideas from the designer's head into reality, enabling communication and feedback.

Context of Conceptual Models

Models vary by context, such as:

Systems Design: Defining architecture, components, and interfaces.

Service Design: Organizing infrastructure, communication, and components to improve interaction quality.

Product Design: Generating and developing ideas into final consumer products.

Advantages of Conceptual Models

Shared understanding

defines scope

allows iterative refinement

identifies early problems

simplifies complex ideas for non-designers

enables safe simulations (e.g., crash tests).

Disadvantages of Conceptual Models

May not work in real-world settings

lacks detail and may lead to misinterpretation

simplicity might overlook vital aspects

Graphical Models

Visual representations (2D/3D) to communicate design ideas, simplify data, and refine concepts.

Freehand Sketching

Quick, rough drawings without technical aids, used to generate and communicate ideas.

2D Freehand Sketches

Easier to create, useful for communicating specific side details compared to 3D sketches.

Perspective Drawings

Depict objects with depth using foreshortening and vanishing points (e.g., one-point, two-point perspectives).

Orthographic Projection

2D views (front, side, top) to communicate a 3D object's dimensions and details, typically used for manufacturing.

Scale Drawings

Accurate representations of an object, reduced or enlarged by a scale ratio (e.g., 1:100 for architecture).

Exploded Assembly Drawings

Show parts of a product separated but in correct assembly order, useful for user instructions.

Formal Drawings

Precise and detailed drawings, created with technical tools or CAD, used for communication with manufacturers.

Physical Models

Tangible 3D representations of a design or system for testing and user feedback.

Scale Models

Scaled-down or enlarged physical copies, used for better visualization and testing.

Aesthetic Models

Non-functional models resembling the final product for ergonomic testing and visual appeal assessment.

Mock-ups

Full-scale representations to gain user feedback, often made from inexpensive materials.

Functional Prototypes

Working models used to test and validate functionality, providing specifications for manufacturing.

Range of Fidelity

The realism of prototypes:

Low Fidelity: Basic representations.

Medium Fidelity: Partial functionality.

High Fidelity: Close to the final product.

Instrumented Models

Physical models equipped with tools to gather quantitative performance data for analysis.

CAD

Use of computer software for designing, simulating, and analyzing systems or products.

Surface Modeling

Photo-realistic exterior models without interior data, used for visual presentations.

Solid Modeling

Complete representations including internal dimensions, volume, and material properties.

Data Modeling

Using structured data (e.g., flat or relational databases) to predict design performance under various conditions.

Finite Element Analysis (FEA)

Tests stress, strain, and performance under specific conditions to optimize material use.

Bottom-Up Modeling

Parts are designed independently and later assembled, favoring experimentation.

Top-Down Modeling

Starts with an overall concept, with parts and assemblies added iteratively to achieve the vision.

Digital Humans

Computer simulations of human aspects interacting with virtual prototypes, enhancing safety and functionality.

Rapid Prototyping

Creation of physical models using 3D CAD data for testing and iteration.

Stereolithography (SLA)

Uses UV light to cure liquid resin into solid forms. Advantages: High precision and smooth surfaces. Disadvantages: Expensive, limited material durability.

Laminated Object Manufacturing (LOM)

Cuts adhesive layers to form 3D models. Advantages: Fast, accurate, and suitable for large parts. Disadvantages: Poor surface finish, waste generation.

Fused Deposition Modeling (FDM)

Extrudes melted plastic layer-by-layer. Advantages: Cost-effective, strong materials. Disadvantages: Visible layer lines, slower build times.

Selective Laser Sintering (SLS)

Uses a laser to fuse powdered materials into solid shapes. Advantages: Excellent for complex geometries and small batch production. Disadvantages: Expensive equipment, potential thermal distortion.