- Development and implementation of quality plan
- Continuous on-site quality control
- Rapid intervention when resolving quality issues
It is to both the customer’s and the supplier’s benefit that the product quality control plan is comprehensive. The quality standards should be defined for not only the finished product but also every sub-assembly and part. A vaguely worded, incomplete plan will only result in misunderstandings between both parties as to what the deliverables are. Conversely, well-defined quality requirements will eliminate any ambiguity and if adhered to ensure that the product is produced to a consistently high quality level. Also, if issues do occur, with a comprehensive quality plan there is clarity as to what constitutes a defect.
Porticos Asia will often help the customer develop the product quality plan by making suggestions for more generic standards such as cosmetic standards, whilst the customer, having a more intimate understanding of the products’ performance requirements, will define standards specific to their design. Developing a quality plan is a slow process, typically, numerous iterations are needed. For this reason, work should be started at an early stage in the product development cycle to allow time for quality criteria to be fully defined by the start of the first engineering sample builds.
The first step is to prepare a master product quality plan delineating the standards at a top level. We will then translate this master plan into working documents and design and build quality control jigs and fixtures for implementation during the first builds. The quality plan is a live document. This means that not only can adjustments be made following each build leading up to the product launch but also after launch the plan can be revisited as necessary and changes made in light of experience gained during production and from the field.
A quality plan can be broken down to the following sections corresponding to stages in the production process:
Incoming Quality Control (IQC): During IQC parts and materials are subject to a series of checks prior to allowing them on the production line. These checks can include the measurement of critical dimensions, checking of material certificates of conformity, electrical tests and visual inspections.
In-Process Quality Control (IPQC): IPQC refers to checks implemented during production. For a custom mechanical part (die casting, plastic injection molding etc.) these can include the checking of molding parameters, ensuring correct raw material preparation and the control of critical dimensions, For a PCBA, checks can include the checking of electrical parameters to ensure compliance before final assembly.
Outgoing Quality Control (OQC): As the term implies OQC is carried out at the end of the production line on the final product. Functional testing, a series of checks replicating product use, is implemented as well as other visual and dimensional checks. Typically, a customer will replicate the outgoing inspection carried out at the factory during the incoming inspection at their facility. This way, any disagreement regarding the suppliers’ responsibilities can be eliminated.
Reliability Testing: This testing can be carried out during the product development stage only to ensure materials and parts meet performance requirements. On the other hand, it can be repeated, in full or in part, for every production batch as an extra level of quality assurance. Such testing can include cycle testing such as the opening and closing of a cover multiple times, environmental testing (temperature, humidity, salt spray etc.) to ensure a product’s functionality under different ambient conditions and burn-in testing to confirm longitudinal standards are met.
It is worth noting that in addition to the above-mentioned quality processes in relation to the product, the equipment itself used to implement these processes must be subject to regular checks. If the accuracy of the measuring instruments is not regularly confirmed then the data they produce cannot be relied on.
Simply defining standards and handing them over to suppliers for implementation does not suffice. Without being on site to ensure quality processes are followed for every production run, from the manufacture of parts to the finished product, quality issues can occur. Prevention is far and away preferable to experiencing problems in the field. Only by constantly and directly ensuring quality processes are followed can costly quality issues after products are bought by end customers be avoided with certainty. In a study carried out by us for one customer it was found that the costs of addressing quality problems after products had been purchased by end customers added approximately 20% to the product’s price. Furthermore, this analysis only focused on the tangible costs such as travel costs and costs for returning and reworking products. Less easily measurable financial impacts such as the damage to brand equity were not included and are perhaps even more damaging.