Serial delivery

1. Complaint department

If WIKA recognises a deviation of the bought-in products, WIKA complains about the deliveries (in isolated cases also parts of the delivery) and sends them back to the supplier. If it may be necessary to rework or sort out the products at WIKA for reasons of meeting deadlines, the supplier must agree upon the activities required prior to reworking or sorting out the products and the costs incurred are passed on. Each complaint is reported to the supplier by means of a test report and has effect on the supplier evaluation.

2. Comment / 8D report

If WIKA requests a written comment from the supplier in case of a complaint, the request is clearly recorded in the test report with indication of the deadline. The supplier must send the comment as 8D report within the deadline to the e-mail address If it may not be possible to send the comment within the required deadline, the supplier must inform WIKA by sending a short message, including the new deadline, to the same e-mail address. If the comment is not sent to WIKA in time, a reminder will be sent.

3. Technical changes

Technical modifications of the product or the manufacturing process at the supplier must be reported, planned and carried out early in agreement with WIKA. After each modification, WIKA reserves the right to re-sample the product or to revaluate the process on the basis of a process sign-off.

Modification on the initiative of the supplier

The supplier must request the modification of an approved component from the responsible WIKA Lead Buyer. WIKA decides internally if the modification can be carried out. The modification may be carried out only after approval. An advance plan guaranteeing the supply until the modification is authorised must be presented in agreement with the WIKA Supplier Quality Engineer.

The following modifications require a new first article inspection:

  • Modification of the product design
  • Modification of the material or substance
  • Modification of the product manufacturing process
  • Application of new or modified machines, tools or equipment
  • Assignment of new subsuppliers
  • Relocation of the production

If a new/second sample inspection of the product is required due to technical modifications, WIKA will order samples and provide the first article inspection file (EMPB report) to the supplier. The responsible WIKA Supplier Quality Engineer must agree upon the extent of the first article inspection.

Modification on the initiative of WIKA

After a modification, WIKA will provide the technical documentation, such as drawings and/or specifications, with a new index and provide it to the suppliers. On request, WIKA gets an offer (costs and deadlines) and a producibility evaluation of the requested modification. The drawings will be modified only after accepting the offer and confirming the producibility.

The extent of the first article inspection will be defined by the responsible WIKA Commodity Team.

4. Deviation Request

If a supplier recognises that the product differs from the technical documentation, the supplier can inform WIKA by means of a Deviation Request. The supplier must send the filled-in request, including the WIKA subject number and order number, to the responsible Supplier Quality Engineer. Note: The supplier must fill in the complete form sheet! Particularly important are the failure cause and the remedy.

WIKA checks internally the usability of the product and informs the supplier about the decision by sending the filled-in deviation request to the supplier. Products delivered due to an authorised deviation permission are not considered negatively in the supplier evaluation.

5. Process audit

WIKA reserves the right to audit the manufacturing process and all processes relevant for supplying WIKA at any time and after agreement with the supplier. Reasons for an audit may be: qualification of a new supplier, conclusion of a quality assurance agreement, considerable deterioration of the quality performance of a supplier, approval of new/modified processes and tools. WIKA performs process audits based on VDA6.3. The audit is planned in agreement with the responsible body of the supplier. After carrying out the audit, the supplier is informed about the result within one workweek but normally the same day. If improvement measures are required due to the audit result, the supplier must elaborate an action plan and send it within the deadline to the WIKA Lead Auditor. If a re-audit may be required due to the occurred deviations, the re-audit must be agreed upon with the responsible body of the supplier.

6. Quality of the series

Quality assurance agreement

The quality assurance agreement is a document accepted by both parties describing the basic principles of collaboration with focus on the activities related to quality and production. The quality assurance agreement is not product-related. WIKA aims to conclude a quality assurance agreement (see annex) with the suppliers that already have proved extensive experience and high technical reputation in development, manufacturing and supply of the products. The aim of such a quality assurance agreement is to reduce or avoid costs induced by warranty claims (claims due to product liability) and to increase the efficiency of collaboration.

Serial Test Report

The Serial Test Report is an inspection specification document that describes the WIKA test requirements with respect to the part and that is agreed upon with the supplier. The aim is to enable the supplier to check and document in-house all WIKA requirements to comply with for the incoming inspection. The report on the series can only be concluded on the basis of an existing quality assurance agreement. WIKA and the supplier agree upon the deadline of sending the test documents after concluding the quality assurance agreement and the report on the series. If no particular requirements are given (e.g. safety-related criteria), after sending 5 error-free deliveries it is no longer necessary to send the test documents. The Serial Test Reports are subject to the WIKA modification service, i.e. technical modifications are recorded in the report on the series and provided to the supplier for agreement or information. The supplier is also obliged to inform the WIKA SQE about the modifications concerning the extent of the Serial Test Report (e.g. modified method of measuring).

Boundary sample

The quality of special features that cannot be measured can be checked by means of boundary samples by creating a visual approval standard. The boundary samples have to be marked on the corresponding position and be provided with date and signature. The responsible WIKA SQE evaluates the samples and approves them in writing. The supplier is responsible for the control of the modification status, the usability and the regular inspection of the boundary samples.

7. Rework

A process defining the method, qualification of the employees and the qualification of the parts after processing must be defined in order to be able to rework the parts. The parts reworked by the supplier that may be provided with a special marking on request of WIKA and are supplied separately must comply with all requirements of the specification. The method and extent of the rework must be discussed and agreed upon with the WIKA SQE.

8. Quality objectives

WIKA reserves the right to conclude quality objectives in form of, for example, PPM with selected suppliers.

9. Continuous improvement process (CIP)

The supplier must continuously analyse and optimise its processes related to the manufacturing process. The results gained are used for the consequent implementation of improvement measures and control of the effectiveness.  The measures must be documented and the corresponding documents must be handed out to WIKA if requested.

10. Supplier evaluation

At least once a year WIKA performs a supplier evaluation for selected suppliers. The supplier gets the results and must present a suitable action plan for improvement to the responsible Lead Buyer.


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