Selection of suppliers

1. Supplier qualification

Quality management system
As a minimum requirement, WIKA expects its suppliers to prove that they have an effective quality management system meeting the requirements of the standard series ISO 9001. The standard requirement in accordance with IATF16949 is applicable for suppliers whose products flow into the automotive industry in their further use. The current certificate of an accredited certification body is regarded as evidence for the implementation of the aforementioned system. Any change in the certification status must be communicated without delay to the responsible quality employee of the supplier development (SQE) of WIKA.

Environmental management system
WIKA suppliers should be certified like WIKA in accordance with EMAS or ISO 14001 or, at least, be able to present a documentation about regular improvement measures regarding the environment. The supplier commits to observe the legal limit values during the production of the parts and regarding the materials used for the manufacturing processes, even though those values represent only minimum requirements. Modifications of these requirements by legislation have to be taken into account, but need not be communicated to WIKA. Examination results as well as information on the supplier and environmental management must be presented without request.

2. Self-assessment
New suppliers are first evaluated on the basis of a standard self-assessment form. This form includes general questions about the company size / structure / legal form / technology / resources / QM system... On the basis of this self-declaration, the commodity team consisting of the Lead Buyer (purchaser), SQE (Supplier Quality Engineer, supplier development) as well as the SLE (Supplier Lead Engineer, technical support) decides on the further procedure. A QP employee (Quality Purchasing) is additionally involved in the scope of a new product project development. This person is the contact partner for quality and purchasing topics for the duration of the project.

3. Pre-audit and process audit
Before placing an order, WIKA can carry out a pre-audit for potential suppliers which is based on the WIKA checklist. The purpose of the pre-audit is to check the ability of a new supplier to fulfil WIKA requirements in order to provide one of the bases for deciding on a further cooperation with the supplier. When the audit is finished, the supplier will be informed on the audit result within one working week. If the audit result requires improvement measures, the supplier must elaborate an action plan and send it to the WIKA lead auditor within the agreed period of time. A follow-up audit is not intended with this audit form because a mandatory process audit is performed when the contract is awarded in which all issues which are still open from the pre-audit can be checked.

The process audit is then performed to the final process approval and is temporally oriented to the initial sampling, as a rule. The process audit is performed by the supplier developer (SQE) of the relevant commodity team or, in case of new projects, by the responsible QP employee (Quality Purchasing). With reference to the action plan, the procedure for the process audit is the same as for the pre-audit, however, a follow-up audit could be carried out due to the audit findings.
Both audits contain the elements of the questionnaire in accordance with VD 6.3. The classification/ evaluation of the pre-audit and the process audit are conducted in accordance with VDA 6.1 taking the features that are necessary for WIKA into account (see next point).

4. Rating and approval
A degree of compliance (in percent) is determined on the basis of the individual assessments. The following classifications are accordingly possible for suppliers:

  • >= 90 percentage points        -> A classification
  • >= 80 < 90 percentage points -> B classification
  • < 80 percentage points          -> C classification

5. Feasibility declaration
The feasibility assessment is made to evaluate whether a requested part can be manufactured according to the requirements (drawing / specification) under series production conditions. The supplier is responsible for the feasibility assessment which offers him the chance to contribute his experience and to make proposals for the benefit of both parties. This should ideally be carried out in cooperation with the responsible lead buyer / project buyer as well as with the employee of the design and construction department or SQE of WIKA. Given tolerances under statistical aspects as well as the function and load of the product must be particularly observed. Furthermore, a statement is to be made as to whether the supplier's capacity is sufficient for the delivery of the planned quantities and whether the scheduled delivery dates can be met.

Methods that can be used for the feasibility assessment are, for example:

  • Design of Experiments (DoE)
  • Failure Mode and Effects Analysis (FMEA)
  • Process Capability Analysis (SPC)
  • Fault tree analysis / Ishikawa diagram

6. Supplier development
The supplier development of WIKA offers the opportunity of the further development of existing QM systems in terms of the standard requirements ISO 9001 or IATF 16949. WIKA is prepared to provide support to its suppliers with information, know-how and expertise. This can be done, for example, by regular supplier assessments, a clear definition of the documents and procedure required for sampling inspection, training to use the WIKA-specific tools and general quality tools (e.g. FAI, 8D, Ishikawa, 5 Why), conclusion of a Quality Assurance Agreement (QAA) and the definition of clear goals (e.g. ppm, reliability of delivery). In addition, WIKA reserves the right to carry out a system, process and/or product audit, in order to check on site that the quality management system is effective. Furthermore, the supplier is responsible for the development of his sub-suppliers.