PART 1 CONCEPTUAL PHASE
Creating an all-new new vehicle is one of the most daunting challenges for any company
In our consumer-driven society, new or revised vehicles are launched on a weekly basis because customers expect their set of wheels to fulfil their everevolving requirements on safety, performance, longevity and affordability to purchase and run. Therefore, spare a thought for automakers that spend vast amounts of capital to create vehicles in the hope they will achieve sales success. In this first instalment in a series on vehicle development, we look at how a car is born.
PRODUCT DEVELOPMENT
Every automaker has a product development department that plans future vehicles. Automotive fashion has an enormous influence on this department’s decision-making, as can be seen in the popularity of compact SUVs and crossover products. With the help of the OEM’s marketing department, future-client profiles are drawn up in detail to represent potential customers in a certain segment. Such a client profile can include age, income, education, marital status and number of children, etc. and is usually named, for example “Bob”. When a vehicle is planned for a specific customer profile such as Bob’s, it needs to fulfil all his vehicle requirements when it goes on sale.
Time to market is critical; the shorter the lead time, the better the chance of sales success. A vehicle that initially seemed a sure seller can easily turn into a showroom dud when it is produced four years down the line owing to changing market conditions and rapidly advancing technology. To design and build a new vehicle takes substantially longer than simply changing the body shape on an existing platform (chassis) and using an existing powertrain (see Programme scaling on page 128). Therefore, it is rare to see an all-new vehicle (upper body, platform and powertrain) due to the immense complexity as well as the delay in getting the product to market.
USER REQUIREMENTS
One of the most important and secretive documents relating to a future vehicle is the user requirement (UR). This document depicts the exact requirements of the proposed owner of the vehicle at the time of production; think of it as the crystal ball of the development team. As an example, the UR documents of vehicles developed today may not include CD players as part of the infotainment package because MP3s and Internet radio are the preferred media of the future.
The UR normally consists of the following categories and explains the content in very fine detail:
• Derivatives – specifications levels of different model derivatives;
• Styling – exterior, interior;
• Driving experience – handling, braking, performance, efficiency;
• Comfort – vibration, noise, engine sound;
• Infotainment – audio, connectivity, navigation, displays;
• Practicality – exibility of seats and loading area;
• Safety – crash rating (example: EuroNCAP);
• Environmental impact – direct and indirect emissions, recycling;
• Lifecycle changes – mid-model-life facelifts;
• Benchmarks – important opposition-vehicle qualities;
• Target markets – countries where vehicles will be sold;
• After sales – dealership experience;
See the example table to the below.
The following table lists possible UR criteria of a future vehicle. Note that the UR can easily have more than 2 000 entries:
ID | CRITERIA | EXAMPLE STATEMENT |
UR0001 | Sporty performance | The vehicle will have sporty performance |
UR0002 | Power steering | The vehicle will have speed-dependent power steering |
UR0003 | Centre screen | The centre screen will have touchscreen |
UR0004 | Turning circle | The turning circle will be best in class |
UR0005 | Efficiency | The vehicle will be fuel efficient at highway speeds |
PLM SYSTEM
Due to the complex nature of a new vehicle, it is impossible to keep track of all its requirements and regulations. Programme lifecycle-management (PLM) software is used to share and store requirements, schedule events and make decisions about the programme. Levels of access and security are allocated to users (engineers, planners and management) so that they access only the information they need. Each requirement is numbered and linked to the technical specification created. During the validation phase, each requirement will be signed off. Management plays a big role in the process to ensure the programme stays on schedule. The PLM software can even contain links to the actual computer-aided design (CAD) drawings of the vehicle and link each component and system to a requirement.
REGULATIONS
The vehicle has to meet all type-approval regulations of the global markets in which it will be sold. For passenger vehicles in Europe, the class of regulations will be M1 and fall under the European Commission whole-vehicle-type approval (EC WVTA). These regulations must be adhered to and are of higher importance than the UR document because a vehicle that fails to meet these requirements may not be offered for sale. These regulations cover the entire vehicle, with some of the example categories including:
• Emissions requirements;
• Safety – crash safety, electrical safety, general safety, vision angles;
• Performance – braking, headlamps, wipers;
• Audible devices – hooter, pedestrian protection in EVs;
• Permissible sound levels – exhaust, tyre noise;
SYSTEM V
The System V process is often used by development engineers to visualise the design process. By applying this concept to a new car, it can be seen that the vehicle is conceived at vehicle level. Only when targets are set can engineers move to the system level and thereafter the component level. When the lowest point of the V is reached, a total production design exists for the complete vehicle, including all systems and components. The incline part of the second line forming the V is the validation phase. At this stage, testing is commenced on component level and only if the results meet the targets set in the development phase can the engineers progress to system and vehicle level. When all targets are reached at vehicle level, the car is ready for the final production phase.
TECHNICAL SPECIFICATIONS
The challenge for product-development engineers is to interpret the UR and regulations into viable engineering specifications that can be measured. The idea is to not come up with technical solutions at this stage, as they limit innovation, but to pen achievable technical targets on a vehicle level. The next level will be systems, followed by component technical specifications in which actual concepts will be evaluated. A summary of technical specifications is called Book 1 in the automotive field.
See the example table to the below.
This table depicts a subset of possible vehicle technical-specification criteria (linked to the UR requirements on the previous page) and is also the start of the System V process (see page 126) that covers most of the development process:
ID | CRITERIA | EXAMPLE STATEMENT |
TS0001 | Acceleration (0-100 km/h) | Less than 8,0 seconds |
TS0002 | Power steering | Variable-rack electric power steering |
TS0003 | Centre display | Larger than 12-inch with touchscreen functionality |
TS0004 | Turning-circle diameter | Less than 10 metres |
TS0005 | Drag coefficient | Less than 0,26 Cd |
PROGRAMME SCALING
Below is a typical table used by major OEMs when determining the scaling of a new programme. The vehicle is divided into three segments: chassis, upper body and powertrain. The code will influence the timescales and complexity of the programme, as well as the resources needed. Example: an existing vehicle receiving only a new powertrain will be coded 1-1-6; no change to chassis or upper body but a new powertrain. An all-new vehicle will be coded 6-6-6 and is informally referred to as the devil’s programme due to the huge complexity, cost and risk.
SCALE | CHASSIS | UPPER BODY | POWERTRAIN |
6 | All-new | All-new | All-new |
5 | Major suspension and floor changes |
New inner and outer skin; retain structure |
New derivative |
4 | Major floor change | New outer skin only | Modified extensively |
3 | Partial floor and suspension change |
Fenders and bonnet only | New installation of existing engine |
2 | Suspension tuning only | Bumper, lamps and grille only |
Minor layout changes |
1 | No change | No change | No change |
THE FUTURE OF CAR DEVELOPMENT
Automakers aim to reduce development time of new vehicles. Computer-simulation software has reduced times considerably because a complete new vehicle can now exist in the software domain. Models will become ever-more dynamic, to the point where the handling and performance can be assessed before a single weld is made. Welcome to a world where new vehicles will be launched on software platforms where you can “drive” them before they exist. OEMs can save billions by canning unwanted products before they reach the production line.