Automotive Wiring Harness Cost Control and Analysis

Automobile harness is the main network of automobile circuit, which is used to connect various electrical appliances. Its function is similar to the blood vessels in the human body, and it is the channel of current signal. The automobile harness is mainly composed of wires, connectors, terminals, clips, tapes and other auxiliary materials. The competition pressure in the modern automobile market is great. In order to achieve a win-win effect, we, Kable-X, need to ensure that the Wire Harness, we produce, meet the quality requirements of customers and achieve higher benefits at a lower cost. To control the cost of automotive Wiring Harness products, we first need to improve the eligibility and accuracy of the cost analysis of parts, carry out a series of analysis and research on the cost of parts of automotive wiring loom types, and use a variety of different analysis methods to select the appropriate control method to control the cost of automotive wiring harness products.
1. Design of Harness Products
The service object of the wire harness is the load source, which refers to the wire harness assembled with other parts, which is the carrier for transmitting power and accelerating signal transmission, and the communication link in various fields of automobiles.
1.1 Types and Composition of automotive wiring harness
According to the structure of automotive wiring harness, it can be divided into full utilization harness, partial utilization harness and link system. According to the different service modes, it can be divided into loss harness and waiting harness; According to the number of attached sources, the service can be divided into unlimited load harness and limited load source harness. Besides these, there is another classification, that is, it is divided into main harness and small harness. This statement is distinguished according to the number of parts. Among them, the main harness includes engine harness, floor harness, instrument panel harness, etc., and the small harness includes ceiling harness, reversing radar harness, door harness, etc.
The so-called wiring harness is to bundle a variety of wires with insulating materials, and integrate wires of different colors and specifications into a whole, which is more complete and unified, and facilitates its safety. 60% of the actual current carrying capacity of the wire and 60% to 100% of the actual current carrying capacity of the wire are respectively applicable to two types of electrical equipment working for a long time and a short time. The cross-sectional area of the selected wire is selected according to the load current of the automobile electrical equipment. In order to recognize the wires in each wire bundle conveniently, different colors and letters representing the colors are adopted. Generally, the wire harness is assembled by plastic parts, terminals, wires, line protectors, rubber parts, brackets, fixtures and other attachments (including tapes and sleeves) according to certain technological steps. If Plato is made according to the proportion of raw material cost of wire harness, the cost of three kinds of materials, such as wires, plastic parts and terminals, is the largest part. The raw materials of wire harness are mainly purchased parts. The main way to control the cost of raw materials is to optimize the cost of raw materials of wires, plastic parts and terminals by benchmarking and VAVE.
1.2 Material Function and Process Production of Wire Harness Products
The wire requirements in various parts of automotive wiring harness are strict and different. Most of them are from the aspects of its electrical performance, temperature resistance and material emission, for example, the wire of engine harness must be high temperature, oil resistance, vibration resistance and friction resistance; The wire on the automatic transmission is resistant to high temperature, hydraulic oil and good stability; The wiring harness on the trunk lid must be selected to keep its inherent elasticity in low temperature environment. Therefore, the cold elastic wire should be selected to ensure its normal work. ABS wire harness needs high-temperature conditions, generally 150-200℃ high-temperature environment, hard insulation and wear resistance, but more than 133 twisted wires should be selected.
The functions of the automotive wiring harness can be divided into two types, one is the power line that carries the power to drive the actuator, and the other is the signal line that transmits the input instructions of the sensor. Thick wires with the function of carrying large current are power lines, while thin wires with the function of not carrying electric power are signal lines. With the change of social demand and the change of science and technology, the functions of automobile modules are constantly increasing. Electronic technology has been widely used in modern new automobiles, and electronic control system is closely linked with automotive wiring harness. At the beginning of this article, it is mentioned that the function of wiring harness is similar to that of blood vessels in human body, and it is an essential element. There is a metaphor: the ECU and other control modules of a car are equivalent to the brain of a car, the sensors on the car are equivalent to sensory neurons, the actuators are equivalent to motor organs, and the wiring harnesses are nerves and blood vessels. At the same time, many contradictions and problems arise when technology is combined with multi-functions of automobiles. For example, how to arrange the automotive wiring harness effectively and reasonably in the limited automobile space, so as to maximize its role and function.
Generally, the process production of automotive wiring harness can be divided into four steps: first, thread opening and crimping process, second, pre-assembly process, third, final assembly process, and finally, final assembly process. The thread-opening process needs to be careful and rigorous, and its accuracy affects the whole production progress. A little mistake will affect the production efficiency. Therefore, at present, most wire harness factories adopt fully automatic wire opening equipment; The crimping process needs to determine the crimping parameters and the required crimping die according to the crimping standards and terminal types of customers. As the crimping quality is directly related to the electrical performance, this station is the key station, and it is necessary to have the crimping operation instructions indicating the special characteristic requirements, and the crimping quality should be spot-checked online in proportion according to the specified process to form the characteristic control chart; With regard to the pre-assembly process, the first task is to make the incoming and outgoing plastic parts of the wire that has been opened and crimped into KIT according to the process instructions, which will help to reduce the investment cost of the assembly line equipment, reduce the difficulty of assembly operation and reduce the number of assembly operators. For simple automotive wiring harness, the pre-installation can be cancelled directly, while for complex automotive wiring harness, the pre-installation station should be set first. After that, it is the final assembly process. According to the process instructions, the pre-assembled wiring harness is arranged on the final assembly tooling board in an orderly manner, and the accessories such as wiring harness arrangement, tape winding, clamping and rubber parts installation are completed. Finally, the final assembly process includes mounting bracket, live detection, full size detection, bundling and packaging, etc.
2 Automotive Wiring Harness Cost Control and Analysis
The cost of wire harness is mainly material cost and production cost. By using calculation method and benchmarking method, this paper analyzes and explores the cost composition of automotive wiring harness parts, and obtains the cost calculation method of automotive wiring harness parts, so as to improve the accuracy of cost analysis of automotive wiring harness parts.
2.1 calculation method
On the premise of a clear understanding of automotive wiring harness's product composition and production technology, through the calculation and analysis of automotive wiring harness's product parts and product structure, as well as the calculation and analysis of the cost of each part, various cost elements can be calculated and analyzed by the calculation and analysis method. The current automotive wiring harness cost includes three parts: raw material cost, manufacturing cost and other costs.
2.1.1 material cost
According to the design requirements of wire harness, the product engineer will design the wire harness product drawings and determine the wire harness bill of materials from the perspectives of material selection/trend/performance. The material cost of each set of wire harness in this project can be obtained through the wire harness bill of materials provided by the product design department and the unit price of purchased parts confirmed by the purchasing department, according to the matching ratio of wire harness models provided by sales and the annual output forecast of vehicle models. The product design decision in this process will directly affect the raw material cost of wire harness.
2.1.2 Manufacturing cost
Through the analysis of the production of technical products, the manufacturing process of automotive wiring harness mainly includes thread opening process, crimping process, pre-assembly process, final assembly and inspection. The cost of wire harness is closely related to the planning of process production steps. For example, whether it is necessary to set up pre-assembly work, whether the ultrasonic station is placed in the final assembly or pre-assembly, and where the magazine is placed will directly affect the production cost of wire harness. The process design of wiring harness is related to the input of equipment, the input of personnel and the planning of site. The whole process design revolves around a goal, that is, how to improve the production efficiency and the utilization rate of existing equipment, site and personnel as much as possible.
2.1.3 other costs
Other expenses mainly include management costs, various development support costs and additional transportation costs, etc. In the early stage of a project, the cost of raw materials plus the manufacturing cost is usually estimated by multiplying the corresponding coefficient.
Other costs = (raw material cost+manufacturing cost) * Coefficient The cost of wire harness is obtained by summarizing the three main types of calculated costs. Compared with the benchmarking method, the calculation results are relatively accurate, but it takes a long time.
2.2 benchmarking method
In the product quotation stage, many parts information is incomplete, so it is necessary to determine the approximate price information of parts by benchmarking. By benchmarking, we can find the similar base point components, and analyze the cost price of wiring harness step by step by comparing the differences. The accuracy of the marked cost price varies to some extent according to the details and accuracies of the information obtained by the benchmarking method, but its advantage is that the forecasting speed is faster. With the development of big data era, with further database analysis as the background, making data model will greatly improve the preparation of price forecast.
3 Conclusion
Focusing on the core values of socialism, in the contemporary society, it is faced with fierce market struggle and rapid economic development, which has expanded the prospect of the whole automobile industry and gained the attention and attention of people from all walks of life. The internal development of automobile industry will focus on how to improve the competitiveness of new product development function and reduce the cost. In the process of developing new automobile products, it is of great significance for the market competition of the automobile industry to establish an economic-centered design concept, reduce the procurement cost after the new products are listed, and maximize the profits of new models. Due to the limitation of time and the relative backwardness of China's science and technology level, besides the calculation method and benchmarking method already discussed in this paper, we should continue to study and discuss.