Working with automotive customers (OEM – Original Equipment Manufacturer), it is worth remembering some good practices about NVH evaluation and production plant involvement that can help the organization during launch and serial production.
In below article we’ll focus on two areas which has big impact on above issues:
Criteria defining for noise and vibration assessment (en. Noise / Vibration / Harness – NVH)
It’s very important that the components for which the is planned FMEA (for product and process) evaluation from NVH point of view has defined appropriate conditions for testing in the car environment. Already in the initial phase of quotation and technical meetings with the customer’s engineering department (eg technical review) organization should ask for information about the test track profile where the vehicles will be tested (height, width, spacing between individual obstacles on the test track and their angle of inclination regarding car wheels).
In addition, it is also worth defining the speed of the car through the test track and its version, because the suspension, eg in the standard version, may differ from that of the drive on both axles.
Picture 1. NVH evaluation examples
The organization must ensure that the information from the test track used for validating the customer’s vehicle and the supplier’s products are consistent with the test track parameters at the customer’s location where the vehicles will be produced. Thanks to this, the organization will be able to avoid potential complaints from the client’s plant for current production.
An ideal solution would be if the supplier’s engineer responsible for NVH would carry out a correlation between the two test tracks together with the client’s engineers (in the place where the tests took place during the development phase and in the client’s location). These data should be used as input data for the process of defining the appropriate frequency ranges for automatic testers (EOL – End of Line Tester), which are usually provided for this type of components.
Involvement of organization production plant at the initial evaluation analysis (RFQ – request for quotation) sent by the client
From the point of view of the production plant it is very important that its appropriate representatives have the opportunity to comment design feasibility of the product sent in the valuation by the final customer. Thanks to this approach, it is possible to verify the assumptions regarding drawing tolerances for significant and / or critical characteristics very early.
By presenting data collected from current or similar projects, the organization may lead to a revision of drawing tolerances by the client even before the formal signing of the contract. Thanks to this operation, organization can avoid additional quality problems that may occur starting from the launch phase in a given customer location.
In this point organization has to remember about main principle: the more time will elapse from production release (SOP – Start of Production / PR – Production Release), then more difficult is for the supplier to push through any changes in tolerance on the product. From the client’s side, a question about the level of production capability presented by the supplier’s process throughout the previous project phases may appear.
Nevertheless, if any quality problems occurs, they should be solved effectively.
It is also important that Project Manager and / or Program Manager, if they are centrally dedicated, have the opportunity to become acquainted with the process of the target production plant of the supplier.
This allows, for example, to avoid misunderstandings related to the incorrect placement of the characteristics, which are measured on fixture (eg, locating them in the place where the fastening devices for its movement are located).
