Conceptual Phase

Author

Professor. Hisham Ibrahim

Conceptual Phase

Summary

The conceptual phase of automotive design is the foundational stage where critical strategic decisions establish the project’s technical and commercial basis. It involves systematically analyzing customer needs and market demands to translate abstract requirements into measurable functional targets. Engineers then define the vehicle architecture, select platform configurations, and specify drivetrain solutions. This phase is crucial as it determines the vehicle’s fundamental character, capabilities, performance envelope, production costs, and competitive positioning, guiding all subsequent design, engineering, and manufacturing processes.

Learning Objectives

  • Evaluate customer requirements and formulate corresponding functional specifications.

  • Investigate market trends and assess their impact on design decisions.

  • Design vehicle architecture that aligns with identified customer needs.

  • Select suitable platforms and drivetrain configurations based on performance criteria.

  • Determine key vehicle dimensions and classify vehicles into appropriate categories.

Customer Requirements Analysis and Market Research

The automotive design process begins with a comprehensive understanding of what customers actually need, not just what they say they want. Customer requirements analysis involves:

Primary Research Methods:

  1. Customer Surveys and Interviews: Structured tools used to gather direct feedback from users about their needs, preferences, and experiences. Surveys provide quantitative data, while interviews offer deeper qualitative insights.

  2. Focus Groups and User Observation Studies: Involve guided discussions with selected users to explore opinions and attitudes. Observation studies track user behavior in real-world or simulated environments to uncover usability issues and design opportunities.

  3. Market Trend Analysis: Involves examining current and emerging patterns in consumer behavior, technology, and industry developments to inform strategic design decisions and anticipate future needs.

  4. Competitive Benchmarking: A method of comparing a product’s features, performance, and user experience against competitors to identify strengths, weaknesses, and areas for improvement.

  5. User Journey Mapping: A visual representation of the steps a user takes to interact with a product or service, highlighting pain points, motivations, and opportunities for enhancing the user experience.

Customer Requirement Categories:

  • Emotional Requirements: Status, style, brand perception, driving experience

  • Economic Requirements: Purchase price, operating costs, resale value

  • Functional Requirements: Performance, fuel efficiency, cargo capacity, seating

  • Practical Requirements: Reliability, maintenance, ease of use, safety

Market Research Integration

Market research provides the context for customer requirements by identifying:

  • Target market size and growth potential

  • Competitive landscape and positioning opportunities

  • Regulatory environment and compliance requirements

  • Technology trends and adoption rates

  • Regional preferences and cultural factors

Functional Requirements Development

Customer needs must be systematically converted into measurable functional requirements that guide technical decisions.

Requirements Translation Process:

  1. Need Identification: What does the customer actually require?

  2. Function Definition: How will the vehicle fulfill this need?

  3. Performance Metrics: What measurable criteria define success?

  4. Priority Ranking: Which requirements are critical vs. desirable?

Example Translation:

Customer Need: “I need a safe family car”

Functional Requirements:

  • star safety rating capability

  • Minimum seating positions

  • Child seat accommodation

  • Advanced driver assistance systems

  • Crash energy absorption structure

Requirements Documentation

Functional requirements should be documented with:

  • Clear, measurable criteria

  • Priority levels (musthave, shouldhave, couldhave):

    • Must-have: These are critical requirements that are essential for the project’s success. If these aren’t met, the project is considered a failure.

    • Should-have: These are important but not critical features. They add significant value but the project can still succeed without them.

    • Could-have: These are desirable features that aren’t essential and can be included if time and resources permit. They are often nice-to-haves that can enhance the user experience.

    • Won’t-have: These are the lowest priority features that are either not necessary for the current project or are postponed for a future release.

  • Validation methods

  • Traceability to customer needs

Technical Specifications and Vehicle Architecture Definition

Vehicle architecture represents the fundamental structural and mechanical framework that enables all other design decisions. Architecture definition includes:

Core Architecture Decisions:

  • Overall vehicle concept and configuration

  • Structural approach (body-on-frame vs. unibody)

  • Safety cell design philosophy

  • Major component mounting strategies

  • Scalability for platform variants

Vehicle Type Selection

Based on customer requirements and market research, designers must select the appropriate vehicle type.

UNECE Categories

Vehicles are classified according to United Nations Economic Commission for Europe (UNECE) standards (United Nations Economic Commission for Europe (UNECE) 2023), which define categories based on vehicle type, weight, and intended use. These classifications are essential for ensuring compliance with international safety, emissions, and performance regulations.

Key UNECE Categories:

  • M1: Passenger cars (≤ 8 seats + driver, ≤ 3.5 tons)

  • M2: Buses (> 8 seats + driver, ≤ 5 tons)

  • M3: Buses (> 8 seats + driver, > 5 tons)

  • N1: Light commercial vehicles (≤ 3.5 tons)

  • N2: Medium commercial vehicles (3.5–12 tons)

  • N3: Heavy commercial vehicles (> 12 tons)

European Market Segments

In Europe, cars are classified into segments as shown in Table 1.1 and Figure 1.1.

Euro Car Segment (European New Car Assessment Programme (Euro NCAP) 2025; Wikipedia contributors 2025).

Segment Name Approx. Length Typical Examples
A Mini 2.7–3.7 m Fiat 500, Smart ForTwo
B Small 3.7–4.2 m Toyota Yaris, Volkswagen Polo
C Medium 4.2–4.6 m Toyota Corolla, Volkswagen Golf
D Large 4.6–4.8 m Opel Insignia, Ford Mondeo
E Executive 4.8–5.0 m BMW 5 Series, Mercedes-Benz E-Class
F Luxury 5.1 m and above Mercedes-Benz S-Class, BMW 7 Series
J Sport Utility Varies as: A-F Jeep Wrangler, Toyota RAV4
M Multi-purpose Loosely B–F Volkswagen ID. Buzz, Ford C-Max
S Sports Usually D–F sized Audi TT, Porsche 911

Market Car Segments.

US Vehicle Weight Classes & Categories

The US Federal Highway Administration (FHWA) categorizes vehicles into eight classes as shown in Figure 1.2.

Types of Vehicles by Weight Class.

Main Dimensions Identification

Once the vehicle’s category is defined, establish the main dimensions:

Primary Dimensions:

  • Overall Length: Total vehicle length including bumpers

  • Overall Width: Maximum width including mirrors

  • Overall Height: Maximum height including roof equipment

  • Wheelbase: Distance between front and rear axle centerlines

  • Track Width: Distance between wheel centers on same axle

  • Ground Clearance: Minimum distance from ground to lowest point

Dimensional Considerations:

  • Regulatory constraints (parking space standards, road width limits)

  • Manufacturing constraints (factory capabilities, shipping requirements)

  • Market preferences (garage sizes, cultural preferences)

  • Performance implications (stability, aerodynamics, interior space)

Platform Selection and Drivetrain Configuration

A platform is the shared foundation architecture used across multiple vehicle models, enabling cost efficiency and development speed.

Platform Selection Criteria:

  • Production volume requirements

  • Cost targets and investment constraints

  • Performance requirements

  • Size and weight targets

  • Technology integration needs

  • Manufacturing capabilities

Powertrain Type Selection

The choice of powertrain significantly influences vehicle architecture, performance, and market positioning:

Powertrain Types

Internal Combustion Engine (ICE):

  • Uses gasoline or diesel fuel

  • Mature technology with established infrastructure

  • Costeffective for current market conditions

  • Emissions and efficiency challenges

Hybrid Electric Vehicle (HEV):

  • Combines ICE with electric motor

  • Improved fuel efficiency and reduced emissions

  • Moderate complexity and cost increase

  • Bridging technology toward electrification

Electric Vehicle (EV):

  • Powered entirely by electric motors and batteries

  • Zero local emissions, high efficiency

  • Requires significant battery packaging

  • Growing infrastructure and market acceptance

Drivetrain Layout Configuration

The drivetrain layout affects vehicle dynamics, packaging, and performance characteristics:

Layout Options

FrontEngine, FrontWheel Drive (FF):

  • Engine and driven wheels both at front

  • Compact packaging, cost-effective

  • Good interior space utilization

  • Common in economy and compact cars

FrontEngine, RearWheel Drive (FR):

  • Engine at front, power sent to rear wheels

  • Balanced weight distribution

  • Better handling dynamics

  • Traditional choice for performance and luxury vehicles

RearEngine, RearWheel Drive (RR):

  • Engine and driven wheels at rear

  • Unique packaging opportunities

  • Traction advantages in certain conditions

  • Found in some sports cars and city cars

MidEngine, RearWheel Drive (MR):

  • Engine between front and rear axles

  • Optimal weight distribution for handling

  • Complex packaging, limited practicality

  • Primarily used in highperformance sports cars

AllWheel Drive (AWD) / FourWheel Drive (D):

  • Power distributed to all four wheels

  • Enhanced traction and capability

  • Increased complexity, weight, and cost

  • Benefits for performance, luxury, and utility vehicles

Integration Considerations

The selected platform and drivetrain must integrate effectively with:

  • Safety requirements and crash performance

  • Manufacturing processes and assembly sequence

  • Cost targets and volume projections

  • Performance objectives and customer expectations

  • Regulatory compliance and testing requirements

References

European New Car Assessment Programme (Euro NCAP). 2025. “Euro NCAP Official Website.” https://www.euroncap.com/en.

United Nations Economic Commission for Europe (UNECE). 2023. “Consolidated Resolution on the Construction of Vehicles (r.e.3).” https://unece.org/fileadmin/DAM/trans/main/wp29/wp29resolutions/ECE-TRANS-WP.29-78r6e.pdf.

Wikipedia contributors. 2025. “Euro Car Segment.” https://en.wikipedia.org/wiki/Euro_Car_Segment. https://en.wikipedia.org/wiki/Euro_Car_Segment.