Before a part, fabrication, or assembly can be added to the Item Master, it must first be reviewed for approval by key individuals that will be directly impacted if the part is put into play. The Design Engineer is usually the person who selects the part for a development effort and therefore has already considered “some” key specifications based upon circuit requirements. The Engineer has already determined such things as the part value, form factor, and critical electrical performance characteristics. Rarely does the Design Engineer cover all the issues surrounding the part’s selection because there are so many departments impacted by the part selection, if the Design Engineer were to cover all the bases before selection for the development project, he or she would be spending an inordinate amount of time on administrative efforts and the design schedule would suffer accordingly. The time consideration is just one reason why another individual, usually the Components Engineer, will dedicate his or her efforts to qualifying the part from not only the electrical considerations, but also with business concerns in mind. Below is a list of questions and issues that are essential to address during a part or a purchased assembly qualification.
1. Does the part already exist in the Item Master, either another class-code, part number, or description? An engineer may have simply missed finding the existing part on the Item Master or previous Bill of Materials.
2. If the part is already in the Item Master, is it on the Preferred Parts List (PPL)? This is the optimal way to develop new designs because the parts on the PPL have already been selected by the Components Engineer because they meet optimal performance and purchasing criteria.
3. Is this component a sole or single source? If so, then the Engineers should be advised to provide them with the earliest opportunity to select a part with a second or alternate source. This is not always possible. In that event, Purchasing should be notified as early as possible to allow for them to check their sources for lead-times and costs.
4. Is the part just an early engineering sample with datasheets marked as “Preliminary” and not yet in volume production? Preliminary datasheets are a heads-up that the specification for the final versions may change and therefore may not be 100% reliable as a development component.
5. Is there a less expensive alternative part that would save the company some money?
6. Has the part or manufacturer been previously disqualified from the Item Master for cause? When there are historical disqualification or obsolescence records for part dispositions, they should be consulted to avoid designing in disqualified parts on the new development.
7. Has Purchasing or Materials previously disqualified the supplier from the AML (Approved Manufacturer’s List) or AVL (Approved Vendors List)? The engineer may not be aware that a manufacturer has been disallowed for business reasons or because they failed a supplier quality audit.
8. Is the component’s form factor optimal for manufacturing and test purposes? An example might be a part in both a through-hole and a surface mount package. Has the least assembly or test cost been taken into consideration? This is a Design for Test (DFT), Design for Assembly (DFA), or a Design for Manufacture (DFM) discipline. Sometimes the Assembly or Test operations people should be consulted to help make the decision.
9. What are the reliability issues with the part? The operating environment may set the criteria for temperature, vibration, and other stress related concerns.
10. Is there a complete specification document from which to develop the electrical testing qualification process? This is the only way to determine if the manufacturer’s part performs as stated in the specification and as the Design Engineer intends. Do not trust Datasheets! They are rarely 100% accurate.
11. Has Purchasing given a preliminary approval based upon early RFQs from suppliers? If Purchasing says the part is on allocation, or unavailable for any number of reasons, then the Design Engineer should be notified at once and the Components Engineer should suspend the qualification process.
12. Can the Manufacturer’s Representative or Salesperson supply enough samples to allow for a sufficient sample quantity for board level testing?
13. Has the supplier completed a “Component Information Request Form”?
14. Does the company have the equipment and expertise to test the proposed part in house or does it need to be tested at an outside facility? If shock, vibration, temperature, FCC compliance, Regulatory, Safety, and other environmental considerations are critical qualifiers, then the resources must be allocated prior to part approval.
*Refer to the procedures and forms on this website for Part Qualification.