Voiceover narration: “In the quality management system, the products are represented by two separate yet equally important groups: The quality control professionals who investigate the crimes against product quality, and the quality assurance experts who proactively prevent defects, variances, and other product quality offenders. These are their stories.” (Insert “dun-dun” clang sound here.)

QA and QC are not identical or interchangeable, but you’re likely to have peers who don’t understand the distinctions between them. To help such individuals solve the mystery behind these frequently conflated quality functions, you can provide an example of QA and QC that draws a comparison to something so ubiquitous that almost anyone can relate to it: the television show “Law & Order,” whose various iterations have been broadcast onto our screens for what seems like as long as manufactured products have been advertised on TV commercials.

Quality Assurance: Laying Down the Quality Law

Before production even begins, the QA department (even if it’s just a department of one) is responsible for establishing the organization’s quality “laws.” Think of quality assurance as the legislators who establish the law the despicable criminal is about to break in the opening scene of the “Law & Order” episode. Their primary goal is to prevent the manufacture of nonconforming products by establishing a quality assurance plan for manufacturing.

QA’s objective in designing procedures, specifications, and process controls is to optimize production outputs so that the organization’s controlled processes result in a quality product. QA is continually focused on eliminating process variation. When the explicitly defined procedures QA has created, refined, and implemented are precisely followed, product quality is ensured. And just as those legislators that established the laws that dictate the legal system are separate from the groups that enforce and prosecute those laws, the QA function is independent of manufacturing and operations.

The QA function also serves vital post-production roles. QA teams implement process improvements whenever possible and lead efforts to investigate, correct, and prevent any quality issues that have occurred. So if you see someone interrogating a coworker on the production floor like Ice-T shakes down a sketchy suspect, it’s probably someone from QA investigating potential root causes of a quality problem. Just politely ask them to dial down the bad cop routine and focus their efforts on the core QA responsibilities that help preserve continual production reliability, which include the following:

• Change control.
• Corrective action / preventive action (CAPA).
• Customer complaints.
• Device history records (DHRs)
• Device master records (DMRs).
• Document control.
• Environmental control.
• Finished product release.
• Inspection sampling plan development.
• Internal quality audits.
• Label control.
• Nonconforming material investigation and disposition.
• Quality trending, record control, and system management review.
• Statistical technique selection.
• Supplier corrective action.
• Supplier evaluation and monitoring.

Quality Control: Upholding Order by Enforcing Quality Laws

QC professionals monitor product quality throughout production. They are the quality “cops” who enforce the laws established by QA. In other words, the main job of QC is to directly measure the output of quality controls and processes. The QC department functions as a resource dedicated to comparing collected measurements to the applicable standards that have been predetermined by the QA team. Like police officers who write reports after a crime has been committed to detail the criminals’ actions and the surrounding events, QC professionals are also responsible for reporting their results in a way that will increase visibility into issues and present opportunities to improve product quality.

While QC is not necessarily subservient to the QA function, product quality control, in the broadest sense, is a mitigating tool that is defined and employed by QA. QC’s core purpose is to detect failures and defects, so it directly interacts with production and manufacturing activities while they are in process. QC has three obligations to fulfill as processes are being carried out:

1. To measure against the established QA specifications to confirm adherence to critical processing parameters (CPPs).
2. To measure products’ critical quality attributes (CQAs) to verify that the execution of processes results in products that meet specifications and standards.
3. To react to observation results by reporting the actual CPPs that were achieved in relation to the CQAs for each lot, device, etc.

QC contributes to continual improvement efforts by reporting the results of and trending data for inspections, testing, and measurements related to activities such as:

• Control and calibration of monitoring/measuring devices.
• Environmental monitoring.
• Final product inspections.
• Labeling inspections.
• Material inspections, handling, and storage.
• Nonconforming material inspection and segregation.

Dig Deeper Into Your Quality Investigation

Understanding the distinctions between QA and QC is only the first clue in your quest to gather all the evidence about quality. But you don’t need to interrogate a confidential informant to get the full debrief. Get a free lowdown on how all quality management aspects work together by downloading the “Quality With Clarity” white paper.