How do I understand VTS/SSTS/CTS in car development?

1. VTS (VEHICLE Technical
): Vehicle technical specifications. Including the technical requirements of the vehicle, the core values, the conditions of the use standard, and the corresponding liability terms.
2, ssts (sub systerm
technical
): System technical specifications. It is a series of requirements for subsystems (features, performance, design) and certification methods.
2, CTS (component
technical): Part of the parts of the component. Engineering documents about the performance of parts, design requirements, and certification methods that meet the requirements of norms.
This first introduces the entire vehicle development phase and electronic and electrical development process, and then develops how to start with market analysis Voice of Customer (VOC). SSTS) and Component
technical (CTS) development, transforming market languages ​​into technical languages.
• The entire vehicle development phase
The vehicle development is roughly divided into 4 stages, as shown in Figure 1:
1)
The starting stage: this stage mainly planned the plan, consider the market Segmentation, product positioning, development costs, production costs and other related factors, and after completing the feasibility analysis of the project, determine the design target framework of the new model.
2)
The concept stage: at this stage, the concept planning of the vehicle, initial design needs, supplier supply capacity, factory output analysis, market activities concept, after -sales concept, innovative design evaluation, vehicle performance evaluation Over the work, the overseas factories with strong design capabilities will also introduce virtual vehicle development technology at this stage to carry out early -stage imitation to assist clear design indicators.
3)
The development phase: In the previous stage, technical indicators are mainly developed. Engineering design at this stage, complete component design, vehicle integration, prototype manufacturing, test verification, pre -production preparation, etc. to meet the design needs.
4)
The mass production/maintenance stage: At this stage, it is necessary to confirm whether the actual product meets the function and physical development needs, confirm the output and quality to achieve the goal, and confirm the cost and profit to meet the economic goals. For the vehicles sold, implementing maintenance and quality assurance activities.
• Electronic and electrical development process
The electronic and electronic development process (V model) we are familiar with, including demand development, design and simulation, component development and verification, integration verification and other stages. The V model will begin in the concept stage of the entire vehicle development stage, and run through the entire development stage to the mass production/maintenance stage, as shown in the yellow coverage area in Figure 1.
The development activities of VOC/VTS/SSTS/CTS proposed herein are mainly located in the demand development stage in the electronics development process. In addition to functional requirements, demand development also needs to consider laws and regulations and non-functional needs (Non-Function
). This part is no longer described in this part due to space.
• Phase 1
-from VOC to VTS
stage 1-from VOC to VTS mainly uses technical languages ​​to describe the performance or characteristics of the market expectation.
In after the marketing department completed a series of market surveys, the VOC research report was released (such as market customer structure, market purchase factors, size positioning analysis, leadership model perception, product attribute importance, etc.). VTS that meets the needs of the market. VTS is the top -level demand, which mainly describes the interaction relationship and performance goals of vehicles and users. It usually includes car space configuration, assembly configuration, performance requirements, gas dynamics, size space, chassis system, car rigidity, external interface, vehicle man -machine interface, air -conditioning system, various modes of NVH, controlling, brake system, life cycle, life cycle , Durability, road safety, vehicle recycling and other aspects.
Ip performance target settings In addition to reference to previous experience and team capabilities, target customer expectations and future trends are key factor. Therefore, the setting of performance goals must be based on deep design experience and effective language conversion. At this stage, a large number of benchmarks and subjective judgments are usually required to support the formulation of performance goals.
we can develop VTS through market input, benchmark analysis, production assembly analysis, simulation analysis, weighing analysis, etc. You can also introduce quality management tools Quality
Function (QFD) as shown in Figure 3 to analyze the basic vehicle information.

• Phase 2
-from vTS to SSTS
This is mainly based on VTS to develop SSTS. The VTS generated in the previous stage has already had a clear indicator for specific performance. It makes it more specific at this stage.
SSTS meets the function of inheriting the first, meet the needs of the previous layer of VTS, and establish the next layer of CTS needs. SSTS has structural disassembly and analysis of complex functions, and defines the combination of multiple components, as well as the interactive information and methods of each subsystem.
SSTS is more specific than VTS, depicting signal interaction, functional logic, scene analysis, and so on. SSTS is more abstract than CTS, and usually does not involve packaging, implementation schemes, detailed principles, environmental testing and other content. Because of abstraction, SSTS has the characteristics of universality. SSTS can independent of the implementation plan, but stipulates a design framework for the implementation plan, so that suppliers can carry out various innovations or reduce cost design in this framework, but they will not deviate from the initial design needs. Therefore, when the car manufacturer selects the supplier solution, it can choose the best quality and cost solutions based on SSTS.
• Phase 3
-From SSTS to CTS
The purpose of this stage is to allocate the function points of SSTS through functional distribution to achieve design requirements to different components. One functional point may be related to multiple components.
CTS is the technical specification of the component. This specification describes the controller design principle provided by the supplier in detail, including the control chip requirements, electrical principles, control functional logic, interactive signals, sleep awakening, electrical characteristics, and performance testing.
SSTS is mainly centered on the subsystem and is implemented by multiple components. The CTS is mainly centered on the controller. CTS is generally provided or confirmed by suppliers, and its content must meet the needs of the demand in each SSTS. The relationship between the three is described below. 4.
This describing functional requirements development work in the process of vehicle development, and introduce the meaning and relationship between VOC/VTS/SSTS/CTS. The performance indicators of the entire vehicle are defined by VTS, which is described by SSTS to describe abstract logical relationships, and CTS explains the implementation plan. Each stage of transformation requires a lot of design experience and support of engineering and technical personnel. It is hoped that readers can understand the appearance of the forward design process through this article. In addition, in terms of development methods, there are two ways, one is TOP-DOWN (from top to bottom), and the other Bottom-up (from bottom to top). To complete a high-platform and easy-to-cut electronic and electronic architecture design, Top-DOWN design ideas must be adopted, which is also the direction of domestic independent brand car companies.

VTS (VEHICLE Technical): October technical specification. Including the technical requirements of the vehicle, the core values, the conditions of the use standard, and the corresponding liability terms;
SSTS (Sub System Technical): System technical specifications. It is a series of requirements for subsystems (features, performance, design) and certification methods;
cts (component technology): parts technical specifications. Engineering documents about the performance of parts, design requirements, and certification methods that meet the requirements of norms.