Prevention Versus Detection: What Are the Main Differences Between Quality Inspection and Quality Control?

Quality Inspection and Quality Control

Quality Inspection (QI) and Quality Control (QC) differ in many ways, subtle as they may seem. The terms broadly apply to manufacturing, but other business sectors benefit like food processing benefit, too. Both concepts make a difference to business success.

Starting simply:

Quality Inspection is typically performed at the end of a process by trained inspectors applying the testing, tools, and standards of the most demanding customer. QI seeks to identify quality issues, inform accountable managers, and advise on the elimination of the problem.

Quality Control refers to the process(es) creating products eventually subject to QI. QA seeks to identify and correct errors and issues during the development and manufacturing process. It succeeds best in an environment and culture where quality is core value and goal.

Of course, nothing’s quite that simple!

QI is a detection process. Depending on the product or service and its complexity, QI is in the hands of an inspector, manager, third-party testing service, and/or customer. It focuses on end-products in post-production testing.

For example, in food processing facilities, QI sets aside poor quality items, so they don’t reach the market. Traditional approaches recycled the rejected materials. Inspectors used checklists, visual guides, chemical testing, and other tools to sort poor products from good products quickly. Management pressed QI for speed and efficiency, so Inspectors did their jobs without feeding information or findings back to managers or employees. Left to itself QI remains a static process without the inclination to improve.

Quality Control is a preventive measure. It works in advance of the inspection process and seeks to reduce the work of QI. QC has a markedly different focus on finding and fixing the source(s) of the error, malfunction, or weakness.

In contemporary systems, feedback is “king.” The ideal QC seeks to reduce or eliminate QI by correcting things at the point of failure. This calls for inspection of all process points to find problems and/or repair or reconfigure the process. Problems might lie in the tools, talents, materials, machines, or even the temperature and lighting at the workstation. However, high-volume and high-quality feedback from QI becomes crucial to QI performance.

Prevention vs. Detection: an obsolete conflict?

Some businesses continue distinctly isolated QC and QI functions, often the result of silo protection. More contemporary organizations build dependency and performance assessment into their cooperation and interaction shooting for an overarching process in which QI feeds QC with the data required to make the business error-free.

Quality Inspection is usually understood as a “pre-shipment” event. To reduce shipment delays, QI will test only a segment of the produced products. The assumption is that inspecting a percentage of the product represents a statistically-sound sample.

The sample is checked for workmanship, safety, functionality, and performance before delivery packing. Purchasers contribute to the process by inspecting deliveries as they arrive for their own set of standards. This customer feedback contributes to improved supply chain management. And, end-users are encouraged to continue the process with feedback.

This circular process improves the reliability of QI’s final inspection without addressing the processes preceding inspection. And, it even has faults. It needs oversight of how the inspected product leaves the factory. Limiting inspection to pass/fail results ignores the definition of poor and medium quality. And, business owners must weigh the cost of inspection against the value of the produced goods. Take SafetyChain, this food quality management software will manage the costs as well as the process.

Quality Control is committed to customer satisfaction and loyalty by confirming and sustaining the business’s reputation for quality and reliability. In some organizations, the QC inspectors stop the production until a unit is removed from the line, until a tool is readjusted, or an item is tagged for recognition at QI.

According to Chron’s Small Business, “Quality-control processes ensure consistency and safety, earning you repeat business. They also cut wasted costs and reduce the likelihood of liability claims and lawsuits.” Quality Control inspectors may roam the food processing facility, manufacturing floor, a research laboratory, an engineering lab, or more. The inspector may examine the incremental production step or review how the on location manager follows standards. In environments lacking the psychological safety that encourages open communication and shared accountability, managers and workers may find QC intrusive and threatening.

Where the work environment proactively encourages and enables, QC is valued for its contributions to customer-centric outputs. In such environments, everyone works within continuous improvement cycles. They understand how the continuous improvement benefits maker and user.

The QC inspector becomes an adviser and mentor concerned with keeping production moving while sharing accountability for quality and customer satisfaction. Without exaggerating their role, as part of the process, QC inspectors make errors, too. Their answers and redirection do not guarantee improvement. But as part of the process, they immerse themselves in the work and share the task to get things right.

Eliminating the conflict:

Quality starts with the customer. The buyer effectively decides what they want in a product and how much they are willing to pay for low-, mid- and high-quality product and performance. When QI and QC merge process, data, and cross-functional interests, customers benefit.

Floor processors, for example, will produce for private brands. Without endangering customer safety and/or violating governing standards, they will produce one level of product for one retailer and another level for a different retailer. Quality is not compromised, but within the expectations of each level, QC must assess performance to those expectations.

QC inspects products in production. Inspectors take samples randomly for on-spot testing. Some contemporary production machines do the testing during the process, but results require monitoring and interpreting. While QI focuses on sorting and rejecting faults, QC works to prevent the variance in the first place.

The best practices align the interests and techniques of QC and QI. All functions and functionaries must understand the customer wants and needs. They work with combined interests and energies toward the same ends. And, they produce and share data to improve future processes. As Forbes puts it, “It’s the difference between tactical quality management and strategic quality management.”

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