The requirements for purchasing are covered in section 7.4 of the ISO9001 standard.

The purchasing process is defined as the process of acquiring goods and services for the purpose of reselling or building proprietary assembles or service. This can include everything from buying hardware to buying complete assemblies. It can also include buying services like outside painting, plating or assembly.

There are basically three areas that are part of a successful purchasing program
1. Selection and maintenance of suppliers (7.4.1)
2. Control and completeness of purchasing requirements (7.4.2)
3. Verification of purchased products (7.4.3)

On this web site, we include verification of the products as part of the inventory control procedure because most companies have a purchasing department that performs the ordering and buying part of the process while the quality or materials group performs the incoming inspection functions. This allows for more focused procedures based on the users. You have the option to create one procedure for both purchasing and inventory control.

Selection And Maintenance Of Suppliers

The selection and maintenance of an approved high-quality suppliers list is an important part of maintaining the quality of your product. Your purchasing procedure should include:

A System For Selection And Evaluation Of Supplier

This is usually done using a supplier questionnaire. The questionnaire. The questionnaire usually begins with a question if the company is ISO 9001 certified. If so then, there is no need to complete the remainder of the questionnaire. You can buy with confidence from an ISO 9001 certified company. If they are not ISO certified, then they must meet other minimum requirement before you can purchase from them. You must define these minimum requirements.

Periodic Re-evaluation Of Suppliers

Periodically you must do and re-evaluation based on their performance. Using non-conforming materials records, you should be able to quickly re-approve the vendors on your list. Because of the extra work required to qualify and re-quality venders, some companies will try to keep their approved vendor list to minimum. This saves time in maintaining the system but will cost the company more in materials and labor since the purchasing personnel can not shop for the lowest price.

System For Identifying Qualified Suppliers during Purchasing Process

Usually the ERP/MRP system will include a flag for approved vendors of each part number. If a vendor losses their qualification, it must be updated on the system. This should be done as part of and Engineering Change Order.

Control And Completeness Of Purchasing Requirements

The second element to purchasing control is definition of the requirements for purchased parts and services. This is usually done using a controlled document with a control number that is somehow connected to the controlling part number. The controlled document is usually created by engineering and should specify all the requirement for the proper part including size, shape, performance, and operation. For off-the-shelf item, you can add your control number to a copy of the general specification from the manufacturer.

Since the documentation is always changing, it is critical to maintain revision control in the purchasing system. The Engineering Change Order (ECO) system should include updating the revision level on the purchasing system as part of any ECO. The ECO system should also include specific information about how to treat the existing inventory, open purchase order, and field installed parts. If the revision change effects the safety or operation of the product, then the open purchased may be cancelled or rejected at incoming inspection. Based on the level of the change, some sniggering change orders can generate a lot of work for purchasing.

See the Engineering Change Order system for information about creation and revision changes of master documents.