For most people, the acronym APQP does not resonate as anything important, but in the world of engineering, it has become a familiar point of reference. Beginning with major industries like automotive and heavy equipment, APQP has trickled its way down to specific components, and many customers are getting sophisticated enough to ask for specific APQP data as a condition of doing business with them. A general outline of what APQP means to the rubber and plastics industry would include a number of considerations.
APQP starts with a control document and raw material specification. The control document must specify measurable product dimensions and tolerances, and accurately reflect constraints such as parting line restrictions, gate locations, allowable flash extension, and allowable radii. It is practically impossible to include every conceivable constraint or to specify any conceivable outcome for the finished product, but generally accepted norms are published by RMA and SPE, and can be referred to by default. The raw material specification should be objectively identified with ASTM (American Standard Test Methods) or better yet, with a specific material, as this will limit variables of different materials that still meet a specification.
The next step for APQP is to coordinate the results of the control document and specifications with a capable vendor, and develop an assessment of capability and competitiveness. A wise engineer will request a “self-audit” of a prospective vendor, and ask them to score their strengths against a checklist of resources that will determine product quality. At this stage, basic variables such as machine tonnage, tool size and complexity, and number of cavities should be reasonably determined. These variables will begin to paint the picture related to product cost, and begin to standardize the competitiveness of the vendors being considered for full production. Paying specific attention to control resources such as raw material test/validation and measurement test/validation should provide advantage, as the better a vendor can validate defined process steps, the less the likelihood that non-conforming product will be realized. A capable vendor should be able to qualify the major variables, and provide a preliminary cost model.
Once the cost estimate is deemed acceptable as a part of the overall project cost model, the unit should be put through a more rigorous design and engineering review, including design for tooling, design for manufacturability, design for assembly, and aesthetics. This is a prime opportunity to catch “downstream” issues before they become obstacles to production. The opportunity is prime because vendor input is normally very valuable in determining these variables, and in developing alternatives and options to improve cost and control. This will also lay the groundwork for the process flow, Control Plan, PFMEA, and Cpk if/when a PPAP is developed.
This design/engineering review should yield a control document and specification that balances required engineering and controls with cost control, and should empower purchasing with the most objective and well-articulated basis with which to negotiate terms with prospective vendors. It should also determine the measurement features and controls for Quality Assurance, so that any validation that occurs at the point of manufacture can be reasonable replicated when the product is received, and apples are indeed compared to apples.
Real Seal has extensive experience in dealing with the sometimes complex task of product development, and can offer considerable value to customers with product development. Rubber and plastics bring unique variables to the game, so the experience, systems, and guidance Real Seal can provide can equate to considerable long term savings.
