Vol. 3, No. 5, May 2019


Case study of quality issues in product development, production, packing & transportation (I)

Case One: Quality issues in the development, production, packing and transportation of aftermarket brake drums

(Continued from the last issue)

Issue Description (2): A client learned that his aftermarket brake drum supplier in China did not have the complete range of items he wanted to purchase, so he asked the supplier to develop the missing ones and provided the drawings. Unfortunately, the new items were not developed and produced exactly as the drawings and the QC staff of the supplier also failed to effectively control the quality of the newly developed models according to the procedures of product development. In the end the client received goods which did not completely match the drawings.

Case Analysis: For aftermarket auto spare parts, customers would typically rely on the OE numbers to identify the models and make the purchase, rarely would they provide drawings as is the standard practice for OE supplies. For the aftermarket factories, most if not all of the products are developed by reverse engineering. Quite often it is hard to confirm if the development samples are indeed the original parts and to ensure the quality of the drawings as well as the completeness of technical specifications and requirements.

After a drawing is received, the factory would usually first check whether they have current products with similar structure and main specifications. If they can identify existing products with similar structure and specifications, they would develop the new items based on the existing products, and some small differences would be easily overlooked or simply let go. Yet when the customers receive the new items, they would check against the original drawings and discover the discrepancies in the specifications, resulting in rejections and quality claims.

In fact, when it comes to new product development by the aftermarket suppliers, we need to undertake evaluations and verifications of their capabilities in product development and production including drawing processing. We should also validate the molding and tooling before the production gets started. Meanwhile, attentions should be paid to the product acceptance standards of each procedure, the parameters of process quality control, the pre-shipment quality control standards as well as inspections before shipment.

(To be continued)

By Felix SS YUAN


Steering Pump

Steering pumps include hydraulic steering pump, electronic steering pump, etc. Hydraulic steering pump provides steering assistance mainly by adjusting the flow speed of the steering fluid. It helps drivers to change the direction of the vehicles by reducing the intensity of the drivers to control the steering and therefore avoiding driving fatigue.

Primary failure modes:


No assisting power: Some interior parts of the pump such as oil distribution discs, motor stators and sliding valves are damaged.


Noise: problems with the steering systems, such as oil leaking from the high pressure oil hoses, noise caused by air intake, or noises from oil being blocking by filter due to dirty oil;


Oil leaking, the engine would burn in serious cases. Causes: rubber aging (high pressure oil hose worn out), oil leaking from the pump, or O-ring missing at the junction of oil can and pump.

Preventive measures and key quality control points:


Each product must be subject to comprehensive testing, including tests of running-in, impact, safety valve adjustment, efficiency, continuity, speed, flow rate and pressure. The appearance and measurements should also be inspected;


Apply stricter air tightness tests before delivery. If the current standard is 0.2mpa for the pressure test, raise the standard to 0.5mpa.



Process Audit

The automotive quality management system standard IATF16949 says the organization shall audit products using customer-specific required approaches at appropriate stages of production and delivery to verify conformity to specific requirements. Where not defined by the customer, the organization shall define the approach to be used.

The product audit is the assessment of the final product and its qualification evaluated against the original design of the product. It ensures a thorough inspection of the final product before delivery.


Cost of raw materials:

Exchange rates:

USD/RMB: 1:6.80

EUR/RMB: 1:7.63

RUB/RMB: 1:0.11

May 2019

The above information is for reference only


The 7th of June, 2019, is a public holiday for the Dragon Boat Festival (or Duanwu Festival) in China.

One of the most important traditional holidays in China, the festival is celebrated on the fifth day of the fifth month of the traditional Chinese calendar. It is to commemorate the death of QU Yuan, an upright and honest poet who died in 278 BC.

Other than the racing of dragon boat during the holiday celebration, an important activity is to make and eat Zongzi (Rice Dumpling) with family and friends.

SHENTOU SUPPLY CHAIN MANAGEMENT CO. LTD. is a Shenzhen, China, based company serving international automotive clients in the implementation of their China strategies and programs. CHINA AUTOMOTIVE SUPPLIER QUALITY MANAGEMENT BRIEFING is a monthly newsletter published by Shentou to address the specific and unique quality challenges and concerns international automotive companies face with suppliers in China. Comments are welcome at Click here to subscribe.

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