2.9: Nonconformance

When a process, product, or raw material is out of specification, it is called a nonconformance. Inspections, audits, and surveillance will occasionally uncover nonconformance or defects. Nonconformance problems are placed in one of three categories based on the product defect: critical, major, and minor.

1. Critical Defect: A defect that knowledge and experience indicate is likely to result in unsafe conditions for people utilizing, maintaining, or depending on the product. When Firestone found that their tires could blow out suddenly, causing accidents, this was a critical defect that triggered a massive recall effort.
2. Major Defect: A major defect is a non-critical error that is likely to result in either product failure (non-life-threatening) or a significant, material reduction in the usability of the product for its intended purpose. If the plastic used in a blender lid, for example, bends in hot water, so it no longer fits the blender and liquids splatter everywhere, the blender lid would be said to have a major defect.
3. Minor defect: "A defect that is not likely to reduce materially the usability of the unit of product for its intended purpose or is a departure from established standards having little bearing on the effective use or operation of the unit." (Summers, 2010). For example, plastic drinking glasses that turn cloudy in the dishwasher, but are structurally sound, is a case of a minor defect.

It must be stressed that these three categories are not the only possible classifications, and a company may define their classes of defects or break these standards down into types of even finer detail. Still, it is important that an employee can determine the impact of a defect and classify it appropriately so that the correct level of response is taken.

Test Your Knowledge!

Read the following news article about a medical device recall.

1. What type of non-conformance was this? (Critical, major, minor).
2. What part of the process do you think failed at catching this manufacturing error? (Inspection, audit, surveillance) Why?

Nonconformance Prevention

Statistical quality control (SQC) is the use of statistical methods to solve problems. Data on the product is collected, analyzed, and used to solve product quality problems such as monitoring and control in the variation of the product. Also, statistics can be applied to analyzing process methods to prevent defects, called statistical process control (SPC). SPC is particularly important in identifying activities that may result in defects and product nonconformance. It's important to note that the use of statistical analysis is essential in moving away from inspecting quality into a completed product and toward making process improvements to manufacturing quality into the product. Hence, the responsibility for quality passes from inspectors to manufacturing design personnel.

Statistical Process Control aids companies in achieving critical goals

1. Consistently manufacture products that meet customer quality expectations.
2. Reduce variability in product quality within and between manufacturing runs.
3. Improve processes by identifying inefficiencies.
4. Minimize production costs.
5. Be solution-oriented and implement changes based on scientific analysis of problems.
6. Assist with the problem-solving process.
7. Increase profits & productivity.

Changing Control Procedures

Deviations or OOS may not be a "negative" but a "positive." It is possible that change will result in improvement, but how is this change incorporated? In a highly regulated process, changes must be taken on conservatively and require the close collaboration of production personnel with quality assurance personnel. All changes must be carefully considered and thoroughly documented. A small change in one aspect of production may have an unpredicted change in another aspect of production or the quality of the final product. Rigorous testing must precede any changes that are instituted.

General Guidelines for change control procedures

1. Review and approval of the (proposed) change by Manufacturing, Materials, Management, Engineering, Regulatory Affairs, QC, and QA.
2. Verification of completion of required studies, reports, etc., supporting the change.
3. Proper documentation of all events surrounding the change.
4. A change control file that includes documentation of approvals, a history of change for each official document, and records and data to support the change.

A change in control procedures works best when it is planned and well thought out. One should ask how the change will affect process efficiency, worker safety, ease of equipment operation, and product quality to name a few. If a problem arises, employees should have the training and the autonomy to do what they deem necessary at the time to prevent significant equipment damage, product loss, or worker injury. Ideally, there is a plan that deals with such emergencies. This should be followed by a change control meeting as soon as possible to discuss and review the incident and follow the regular change control procedure from that point onward. Also, the company should document all activities done during the "emergency" period.

The Future of Quality

The Buddhist philosophy that “Nothing is Permanent” is quite apropos when addressing Quality. Quality systems and methodologies continue to evolve and embrace change along with the pace of new technology products. It is important to remember that the customer affects the future of quality. This is a new, savvy generation demanding value and satisfaction. For organizations to create value, they will need the clarity of the customer's point of view. Quality systems put in place, which are internal to the company, will need to be adaptable and sustainable while attempting to eliminate waste. Competition is the driving force that encourages companies to seek ways to get a competitive edge.