Wiring Harness and Assemblies of New Product Development Process

What is the new product development process for automotive wiring harnesses? In this article, wiring harness engineers mainly talk about project management in the automotive wiring harness industry from the perspective of the wiring harness factory. Accurately grasping the wire harness product development process helps us understand the design and development of wire harness products from a global perspective.
01. Foreword: Project management in the automotive wiring harness industry, accurately grasping the wiring harness product development process helps us understand the design and development of wiring harness products from a global perspective.
Today is an era in which the global business and economic environment is changing rapidly and market competition is becoming increasingly fierce. The development of new products is directly related to the survival of an enterprise, especially in the context of the continued decline of the automobile industry. Therefore, how to carry out a development project well so that the enterprise can achieve sustainable development is a very important issue.
Hi everyone, this is something I’ve been wanting to share with you for a long time. On the one hand, the author is from a technical background, so most of his career has been spent on crafts, research and development, projects, etc. On the other hand, eliminating waste from the front-end new product development process is more consistent with lean practices. Based on personal work experience (from the perspective of a wiring harness manufacturer), let’s talk about project management in the automotive wiring harness industry. Accurately grasping the wire harness product development process helps us understand the design and development of wire harness products from a global perspective.

New product wire harness development process

02 RFQ inquiry
1. New product material identification: Query the supplier website and use the “Supplier Website Link”, as shown below.

Wire harness material composition: classification and identification of wires, sheaths, terminals, hoses, etc. There are also cases where rare ingredients cannot be found online. At this time, you can ask for help in the wiring harness-related groups. Of course, you can also create some supplier resources on weekdays, and even create a database for emergencies.

2. Quotation preparation: Use Excel software to create a circuit table

Special attention: loop table: cells must have content, such as: prenote, double union Vlookup, Sumif, Countif, mastery of mathematical function formulas,
3. Establishment and improvement of BOM table
The production planning department decomposes the BOM table established by the process department into materials required for workshop production, and then adds the process quotas of each standard vehicle model provided to form the materials required for production.

Establishment and maintenance during production
Average and balance all production processes, adjust the workload of each process, make the working time of each process as similar as possible, and balance the working hours between each process as much as possible.03 Process route planning
1. Drawing analysis
① Selection and preparation table, ② Loop wire preparation table, ③ Wire harness directional layout diagram.
2. Process file output
① Basic data statistics
Loop information: loop-by-loop statistics, wire type, wire length, wire material, terminals and sealing plugs.
Steps: Number each sheath on the finished product drawing in sequence from left to right and top to bottom, as shown in the numbers Z1, Z2, Z3, etc.;
②Circuit table production
A. The distinction between straight lines and wiring
B. The information that needs to be expressed in the circuit table, stripping headers at both ends, pre-notes, double parallels, terminals, etc.

Creation of BOM table for wire harness development

The expression of stripping and wiring, the expression of double paralleling
C. Calculation of line length
Tangent length = basic length + auxiliary length + mining length
Basic length = the sum of the dimensions of the same circuit between one or two sheath roots or the sum of the dimensions from one sheath root to the middle outlet.
D. Consider the wiring harness length tolerance

③ Wiring diagram production
A. Expression of wiring relationships, connectivity and orientation;
B. Terminal selection rules (different wire diameters correspond to different terminals);
C. How to draw shielded wires;
D. The contact settings are reasonable;
④ Make pre-installation pictures
A. All straight lines are arranged and pre-assembled;
B. Simple wiring arrangement is pre-assembled (arrange one end of a separate branch) and complicated arrangement is not required;
C. The single-hole sheath is arranged to be pre-assembled;
D. If the terminal is difficult to insert and the sheath is complicated to operate, try to arrange as many circuits as possible;
E. Note that the sheath with lock piece and lock buckle is installed with or without the lock buckle;
F. The use of closed corrugated pipes for branches is reflected in the pre-assembly diagram. If rubber parts and brackets need to be put on first, a reminder must be added;
G. The description of the view direction is combined with the pre-installation diagram;
H. The description of the pullback method cannot be omitted;
Selection of primary and secondary sheaths: Try to select a sheath with more circuits as the primary sheath. If there are many wiring branches, you can directly insert them on the tooling board without pre-installation.

⑤ Creation and improvement of BOM list
1. Based on the drawings, analyze the circuits, casings, sponges, etc., and make a material list for the wiring harness product to reduce the possibility of omissions;
2. Refer to the “ERP Operating Procedures” and enter the material list into the ERP system;
3. After the input is completed, before review, the new product will be checked for the first time according to the “BOM Check Procedure”. Keep the verification supporting information and submit it to the reviewer for review of the BOM;
3. Auditors with the BOM audit authority of the ERP system need to check the verification supporting materials before the audit, and enter the ERP system after confirming that they are correct. Conduct audit operations for products that need to be audited;
Wires, terminals, sheaths, sealing plugs, plugs, clamping feet, lock ties, buckles, brackets, various tubes.
Qualification label, rubber parts insurance card numbered from beginning to end: functional type, casing type. Accessories, etc. need to ensure 100% accuracy in the process and input BOM.
⑥ Drawing and production of tooling drawings
When drawing tooling drawings, the principle is to start wiring from left to right. In order to consider the convenience of on-site work and assembly, branch lines are generally distributed in the first and fourth quadrants.
Ergonomically designed: close to the center of the board on the upper side, with less arrangement on the lower side to minimize bending movements.

Material statistical table for wire harness development

Start laying out the main line from the left side of the tooling board. Based on the principle that there is no need to turn the main line, select paper and tooling board specifications with suitable length. Graphics, pictures, and text should be kept away from the fixture installation area.
Note: Without affecting the tooling layout and fixture installation, the sheath diagram and name can be enlarged in scale and marked with color for easy viewing by the operator.
The numbers are arranged in order for easy search.
Technical requirements such as drawing frames, technical requirements, revision history, design changes, operating points, etc. cannot be omitted.
⑦ Work standard book and inspection standard book
A specific operating standard for the object formulated to ensure the quality and safety of the production process. The homework instruction should be from the beginning to the end of the action, and every action in the middle should be explained in detail.
From the perspective of automobile wiring harness structure, the manufacturing process relies heavily on manual work, and the production form is a labor-intensive enterprise. Therefore, a good work instruction book is easy to understand, with pictures and texts, which helps employees comply with work specifications and achieve visual management purposes.

After the initial preparation of the work instructions, a pre-production review of the production process can be carried out to detect and correct process design defects early and promote process improvement to meet the requirements for continuous product improvement.
Inspection Standards: An inspection performed to prevent defective products from the project from flowing into the next project. Its content includes: inspection items, benchmarks, methods, measuring fixtures, frequency, etc.

04 Output of each stage
1. Comply with the requirements of the program book
“New Product Development Procedure Book”
A. New product manufacturing feasibility report
B. Formation of APQP team members
C. Design brief
D. Initial material list
E. Process flow chart
F. Product Guarantee Plan
G. List of special characteristics of product process
H. Process FMEA
I. PPAP data submission
2. System login and use
Each stage needs to output the form name and list. Complete technical development data, including: drawings, circuit tables, tooling drawings, pre-assembly drawings, BOM, work standards, inspection forms and other process flow documents.
3. Production of third- and fourth-level forms
Goal: All forms can be made according to actual conditions
05 Initial flow management
It is applicable from the start of mass production of new products to three months of mass production or until the quality becomes stable after the quality target reaches the lifting conditions. When materials, construction methods, and equipment are changed during engineering changes, the initial flow time period will be determined based on their importance. During this period, a series of management is carried out to ensure quality and delivery.

06 Conclusion
In new product development, if the product process is not determined in the early stage, appropriate materials and equipment are not selected, and sufficient verification work is not done, it will cause huge losses to later mass production. The analysis of wire harness drawings is a basic and critical task in wire harness processing.
Therefore, the accuracy and efficiency of drawing analysis are very important, and will directly affect the cost composition of the product, such as what standard materials, standard parts, and labor hours estimates are used. Reasonable control of wire harness costs effectively makes wire harness cost analysis more transparent and rational. Therefore, during the development process, reasonable cost optimization is carried out, and relevant test demonstrations are carried out to carry out corresponding substitution and localization of parts and components, which will contribute to product cost savings.
The R&D process, as the precursor to the production process, must always consider how the designed products can be mass-produced. Emphasizes the harmony between customer suggestions and the production process (the goal is to achieve lean production), so more attention will be paid to the participation of relevant personnel in the production process.