Prototyping

Prototype

A physical or virtual (digital) model created to test a concept or process in order to identify potential issues early.

Advantages and Disadvantages of Prototype

Strengths: Communicate ideas; Test functionality; Evaluate usability; Gather feedback; Identify design flaws; Refine; Reduce risks.

Physical prototype

A three-dimensional, tangible representation of a design or a system that can be physically interacted with.

Advantages and Disadvantages of Physical prototype

Strengths: Communicate ideas; Test functionality; Evaluate usability; Gather feedback; Identify design flaws; Reduce risks. Limitations: Limited realism; Technical limitations.

Virtual prototype

A digital representation of a product, often created in CAD and interacted with through simulations or VR.

Advantages and Disadvantages of Virtual prototype

Strengths: Rapid iterations; Cost effective; Remote collaboration. Limitations: Limited realism; Technical limitations.

Aesthetic prototype

A prototype focusing on visual and tactile aspects—form, material, color, texture, and appearance—to evaluate emotional/user response.

Advantages and Disadvantages of Aesthetic prototype

Strengths: See appearance in real environments; Assess feasibility of product. Limitations: Only visual model (non-functional); Fairly expensive; Can be difficult to recreate.

Functional prototype

A prototype prioritizing working aspects—testing systems, performance, usability, safety, reliability, and function refinement.

Advantages and Disadvantages of Functional prototype

Strengths: Tests functional performance; Provides specifications on function and parts. Limitations: Can be expensive; Does not account for aesthetics.

High-fidelity prototype

A refined physical model that closely resembles the final product in materials, finish, functionality, and user experience.

Advantages and Disadvantages of High-fidelity prototype

Strengths: Accurate representation; Precise ergonomics; Usability testing; Good for demonstrations. Limitations: Time consuming; Expensive; Limits flexibility for big changes.

Low-fidelity prototype

A basic, early-stage physical representation focused on form, basic function, and interaction for rapid ideation and feedback.

Advantages and Disadvantages of Low-fidelity prototype

Strengths: Cost effective; Quick; Enables iteration and experimentation; Supports early feedback. Limitations: Limited final aesthetics and materials; May not represent weight or ergonomics.

Scale prototype

Physical models that are full-scale, smaller, or larger than the final product but proportionally accurate.

Advantages of Scale prototype

Strengths: Saves resources; Visualizes spatial relationships.

Performance prototype

A prototype used to evaluate whether a product meets technical specifications, performance metrics, stress, durability, and real-world conditions.

Materials prototype

Used to assess material suitability—durability, weight, texture—and how different materials interact.

Instrumented prototypes / models

Physical models equipped with sensors or measurement tools to collect quantitative performance data.

Advantages and Disadvantages of Instrumented prototypes / models

Strengths: Accurate performance measurements; Records dynamic behaviour. Limitations: Time consuming; Expensive.

Prototyping techniques

The methods used to create prototypes at different levels of fidelity, from sketching to functional models.

Rapid prototyping

A group of manufacturing techniques used to manufacture a physical object quickly for testing aspects of a product, including 3D printing.

Advantages and Disadvantages of Rapid prototyping

Strengths: Speed; Complex parts produced quickly; Cost effective; Allows quick iterations. Limitations: (Not stated)

Selective laser sintering (SLS)

A 3D printing process using a laser to fuse powdered material layer by layer. No support structures needed.

Advantages and Disadvantages of Selective laser sintering (SLS)

Strengths: Handles complex geometries; No support structures needed. Limitations: Higher cost; Materials are expensive; Rough surface finish.

Stereolithography (SLA)

A 3D printing technology that uses a laser to cure liquid resin into solid plastic, producing highly detailed and smooth prototypes.

Advantages and Disadvantages of Stereolithography (SLA)

Strengths: High precision and detail; Smooth aesthetic and functional finish. Limitations: Limited to photopolymer resins; Requires post-processing (support removal & curing); Post-processing is time-consuming.

Fused deposition modelling (FDM)

A 3D printing method that melts thermoplastic filament and extrudes it layer by layer to build an object.

Advantages and Disadvantages of Fused deposition modelling (FDM)

Strengths: Cost effective; Wide material range. Limitations: Lower resolution; Strength limitations.

Drawings

Drawings, manual or CAD-based, used to explore, refine, and communicate ideas.

Advantages of Drawings

Strengths: Visual communication; Supports idea exploration and refinement.

2D drawings

Drawings showing only sides/views without depth; used to show specific sides of a design.

2D drawings over 3D drawings

Strengths: Easier to draw; Cost effective; Clearly shows specific sides; Easy to communicate to audience. Limitations: Lacks depth; Cannot show 3D form.

Informal drawings

Informal (Sketching); used in the development phase of the design process.

used more for the designer to visualise thinking

Formal drawings

Formal (orthographic, isometric, assembly and part drawings); done with great precision and usually with drawing aides (ruler, square, compass) or in CAD programs (Autodesk Fusion).

Can communicate idea to specific audience

Informal versus formal

Informal

Divergent thinking is prominent at this stage

Rapid ideation

Flexibility

Formal

Convergent thinking is prominent at this stage.

Shows in detail

construct accurately

Different views of an object that can’t be seen from a 3D drawing

Time-consuming, requires a high level of skill,

Specialist drawing equipment needed

Free-hand sketching

Informal sketches made without instruments; used for early development and divergent thinking, often with annotations.

Advantages and Disadvantages of Free-hand sketching

Strengths: Rapid ideation; Flexible; Low barrier to entry. Limitations: Lack of precision; Harder to communicate; Cannot manipulate; Cannot send to manufacturers.

Perspective drawings

Formal drawings showing depth with objects appearing smaller farther away; uses vanishing points and foreshortening.

Advantages of Perspective drawings

Strengths: Easy for clients who struggle with isometric/orthographic drawings.

Orthographic projection drawings

Formal technique showing top, side, and front views of a 3D object in 2D for precise manufacturing details.

Advantages and Disadvantages of Orthographic projection drawings

Strengths: Highly accurate; Detailed; Measurement precision. Limitations: Limited perspective; Requires skill to visualize 3D from 2D views.

Isometric drawings

Drawings shown at 30° to the horizon; used for full-product visualization, component placement, and clarity.

Advantages and Disadvantages of Isometric drawings

Strengths: Easier for audience to understand; Dimensionally accurate along main axes. Limitations: Limited perspective; Requires practice (learning curve).

Assembly drawings

Drawings showing how parts fit together; may be fitted or exploded to illustrate part relationships.

Advantages and Disadvantages of Assembly drawings

Strengths: Clear communication of part fit; Helpful reference for assembly; Provides technical documentation. Limitations: Can be complex; Time-consuming and intensive.

Part drawing

Drawings providing material, quantity, and component details, often with a List of Parts (LOP) or Bill of Materials (BOM).

Advantages of Part drawing

Strengths: Provides essential part details; Supports manufacturing and assembly.

Annotation

Notes added to drawings to explain thinking, implications, and relationships between ideas.

Clarifies intent; Shows reasoning; Supports development; Communicates links between ideas.

Computer-aided design (CAD)

Computer-Aided Design (CAD) allows designers to create virtual prototypes. These digital representations enable extensive testing, analysis, and refinement of ideas before physical prototyping commences. Can make both surface and solid models

Advantages of Computer-aided design (CAD)

Virtual testing and simulation; Gathering feedback on complex internal structures or mechanisms; Can provide highly realistic images; As rendering can be presented early in the ideation stage enabling user/client feedback; Reduces the need for a physical model; quicker; Feedback can be received earlier/at a lower cost;

Solid model

representations of the final product that provide accurate data about the product, including internal dimensions and volume, complete machining data. Aiding in designing mechanical parts and assemblies, calculating physical properties like weight and center of gravity and preparing models for 3D printing or CNC machining

Advantages of Solid model

uses to communicate/get feedback from clients/manufacturers; easy to make necessary improvements/modifications; measure the volume; calculate the material quantity/cost; test the structure of materials; optimising the performance

Surface model

Surface model, photo-realistic images of a product, offering no data about the interior of the product, no machining data, no mass, no wall thickness, focused on the aesthetics and form of a product.

Advantages of Surface model

Designing complex, organic shapes; Creating aesthetically pleasing product exteriors; Developing aerodynamic or hydrodynamic forms

Bottom-up modeling

creating separate parts individually then considering how they go together in the final assembly. Small to big

Top-down modeling

Starting with a surface model of the final assembled design, then creating and adding parts to fit that initial vision. Big to small

Motion capture

Motion capture technology records human movements and transfers them to digital models for realistic animations by wearing sensor trackers, leading to dynamic ergonomic data.

Advantages and disadvantages of Motion capture

low cost of animation; saves time; Natural movements; Better ergonomic data Limited to motions that are anatomically possible; Requires a lot of equipment

Generative design

An artificial intelligence-driven software used as an ideation technique to generate a range of digital model solutions.

Haptic technology

technology that allows a user to experience a sense of tactile simulations (vibration) via a haptic device (sensors, PS5 remote, glove, etc), integrating tactile feedback into CAD simulations for interaction with virtual objects. Uses mechanical components to provide physical feedback

Advantages of Haptic technology

Allow users to interact with computer simulation; Present situations difficult to train in real life; Awareness on areas of improvement; provide realistic touch sensations coordinated with on-screen events

Virtual reality (VR)

The ability to simulate a real situation on the screen and interact with it in a near-natural way.

Augmented reality (AR)

A technology that uses a device to superimpose a computer-generated image onto a user's view of the real world.

AR and VR

AR and VR, create immersive environments for real-time interaction with product designs.

Digital humans

are computer simulations of mechanical and biological aspects of the human body. They can be used to interact with a virtual prototype. A digital human library is a collection of digital humans. Digital humans are usually created through motion capture.

Advantages of Digital humans

Can pair with virtual prototypes to generate data; Dangerous tasks can be modelled virtually; Humans of different sizes and weights can be tested; More iterations can be done in less time; reduce cost (but software can be costly); Resolve issues before physical prototypes; Meet human requirements more accurately; Products can be safer due to analysis of safety aspects

Finite element analysis (FEA)

Produces colour-coded results to highlight areas of stress, deformation, temperature; enables designers to understand the stress a part will exhibit under a specific strain early in the development process, allowing the designer to quickly modify, develop the design/materials.

Advantages of Finite element analysis (FEA)

ensure the product can resist impacts/stresses; Reduces the need of costly, time consuming and materials for physical prototyping; Precise quantitative data can be collected; Variations can be tested with consistency; predict how products will perform under conditions that are dangerous or difficult; Helps find safety factors displacement values, max min stress and temp