Qualitätskontrolle in der Produktion

Quality control in production: definition, methods & digital implementation options

Trust is good, quality control is better. And digital quality control is best. But what exactly does that mean? Let's take a look at how you can profitably implement inspections in production and assembly.

Practical example: weasl

Definition: What is quality control?

When we talk about quality in production, we come across a variety of terms. They range from quality management and quality assurance to quality testing and quality control. They are often used interchangeably, but the crux of the matter is that they all have their own meaning and relevance.

In this article, we will focus on quality control and its actual meaning. Quality control refers to procedures and processes that are used to check a product or service against predefined quality criteria. Such requirements can be, for example, specific production specifications, certain standards or customer requirements.

It is important to note that quality control has a clear product-related focus. It is specifically about checking a (partially) manufactured product - with the aim of identifying errors, defects or deviations.

Incidentally, quality control is also often referred to as quality inspection during research. However, we are talking here about quality control as an internal production process within quality assurance, whereas a quality inspection can also be carried out by external service providers.

Quality control vs. quality assurance

Quality control and quality assurance - aren't they actually the same thing? Not at all. Both concepts are part of quality management and represent different levels of it.

Quality assurance is a process-related concept. Roughly speaking, it deals with the advance planning of inspection concepts as well as inspection and measurement systems along the entire value chain.

Quality control, on the other hand, is product-related. It is specifically concerned with checking whether the manufactured product meets the defined quality criteria.

You can read more about the differences between quality control and quality assurance in our blog post on quality assurance in production.

What are the tasks of quality control?

The tasks of quality control all revolve around – you guessed it – ensuring product quality in accordance with predefined specifications. This includes:

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Preparation of the test

All necessary test materials, equipment and test plans are provided.

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Carrying out the test

On the one hand, this includes the actual inspection, for example using reference samples or inspection plans. On the other hand, quality control ensures that all relevant checks have been carried out.

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Approval of products

Does the product or service meet the specifications? Then it is approved by quality control. If not, approval is not granted and follow-up measures must be initiated.

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Documentation

Finally, the results must be documented for internal and external use. Quality control also ensures that tested products are correctly labeled - for example as “rework”, “released” or “reject”.

Does quality control have to be independent of production?

It is not uncommon to find statements to the effect that quality control can only function properly if it is independent of production. But is that really true?

Let's say so: Yes and no. As is so often the case, it depends on a number of conditions. One condition can be the industry. In highly regulated sectors such as the pharmaceutical industry or automotive engineering, the situation is quite different from that in mechanical engineering. Here, quality control must be carried out by specialists.

In manufacturing and assembly, quality control can largely be delegated to the workers themselves. The key to this is a system that enables them to carry out appropriate checks and reliably record the results. A worker guidance system provides valuable services here.

What quality control methods are there?

In a nutshell: You can either check randomly or check everything. What are the differences?

Sampling

Sampling is particularly suitable for mass production. With random sampling, you check the quality either randomly or according to a predefined number of products or shots. You define in advance how large the number of products to be inspected is and how many defects or faults per sample are acceptable.

One hundred percent testing

If you manufacture in particularly small batch sizes or customized products, it makes sense to test every product (or service). Of course, you must also define criteria in advance according to which the products are tested. The only difference is that you check every product and may invest more time in an in-depth inspection.

The intelligent hybrid form: dynamic test steps

You don't have the capacity to carry out a large number of product tests? But you also don't want to rely on static testing every X shots? How about dynamic inspection steps?

Our worker guidance system weasl can - in cooperation with your peripheral systems - dynamically intersperse test steps according to defined criteria.

If decisive quality features deviate from your targets, the system can display additional inspection steps to your workers. This allows you to carry out quality checks dynamically, depending on the situation and as required.

Beyond this, you can also implement decision trees directly in the editor in weasl, which trigger inspection or rework steps as soon as a certain number of defects have been recorded, for example.

What are the advantages of quality control?

Targeted quality controls pay off for your company on many levels. And these range from the optimization of your own processes and procedures to your competitiveness.

Perfect corporate image through high quality

Your good market image

High quality standards strengthen your reputation with your customers. High quality at a fair price pays off much more for you and your customers than questionable quality at a knockdown price.

High customer satisfaction through quality control

Convinced customers who return

If you can ensure that all the quality standards required by the customer have been met, you are not just selling a product. You gain a customer who will come back and recommend you to others.

Quality controls for a high level of quality

Securing your quality level

Once the right measures for effective quality control have been established, you can offer products and services with a consistently high level of quality.

Fewer errors and more profitability

Fewer errors, more profitability

Quality controls help to detect errors at an early stage and prevent defects. You always deliver flawless goods and thus avoid economic and possibly personal damage. Fewer defects also result in fewer returns and reworking, which in turn increases your profitability.

Continuous improvement processes through quality controls

Promoting improvement processes

Continuous quality controls allow you to identify and eliminate weaknesses in your processes time and time again. This promotes the continuous improvement process in your company.

Comply with regulations through controlled quality

Compliance with legal regulations

Do you have to comply with legal regulations or certain standards? Then use quality controls at the relevant points to ensure and document compliance.

More sustainability thanks to quality control

More sustainability

Quality controls can contribute to greater sustainability in various ways: fewer rejects means less waste of resources. Fewer complaints means fewer transportation routes.

And what if there is a problem with quality control?

There is actually no real argument against sensibly established quality controls. On the contrary: there are a few more arguments that you should keep in mind when deciding on an effective quality control system:

  • If complaints arise as a result of inadequate quality control, you will have to spend a lot of time processing them - combined with costs that cannot be ignored.
  • In industry in particular, you should bear in mind that if you have to rectify quality problems on site at the customer's premises, you will be faced with high travel costs and further loss of time. Or you may have to establish additional, expensive technologies for remote services.
  • Recurring quality deficiencies can sooner or later lead to the loss of your customers. Negative reviews or word of mouth will do the rest.
  • If compliance with certain standards and regulations fails due to poorly established quality controls, there is also the risk of losing a license or approval in your industry.

Of course, quality controls can initially incur costs and require technological adjustments. However, the benefits you derive from established testing processes are significantly greater.

What types of quality control are there?

Quality controls can be found at various points in the production process - from incoming goods to outgoing goods. Let's take a closer look at the four basic checks.

Quality control for incoming goods

Incoming Quality Control (IQC)

As the name suggests, a quality check is carried out on the incoming product or component when the goods are received. The aim is to ensure that the outgoing product complies with the specifications and that there are no errors at this stage that may no longer be traceable later.

Quality control during production

In-Process Quality Control (IPQC)

In-process Quality Control (IPQC) involves continuous quality checks during production - i.e. everything that occurs between the incoming product and the end product. IPQC is particularly relevant in the case of strict regulations or requirements.

Quality control of the finished product

Final Quality Control (FQC)

With Final Quality Control (FQC), we have arrived at the last inspection and the final tests of the product before delivery. The aim here is to ensure that the necessary standards for the customer or the market have been met.

Quality control for outgoing goods

Outgoing Quality Control (OQC)

After the final inspection, the product is packaged and provided with the necessary documents. Outgoing Quality Control (OQC) checks that the packaging is free of defects and that all relevant documents are enclosed.

In which sectors is quality control particularly important?

All industries can benefit from quality control. However, there are some industries that are particularly reliant on quality control. In principle, this applies to all industries that manufacture products or offer services that pose a potential risk of harm to humans. These include, for example

  • the automotive industry
  • the pharmaceutical industry
  • medical technology
  • the construction industry
  • manufacturers of cosmetics
  • food producers
  • animal feed manufacturers
  • etc.

For companies in the medical and food sectors in particular, guidelines have already been established that specify detailed quality standards. These include, for example:

  • GxP or “Good Practice” as a cross-industry quality guideline
  • GmP or “Good Manufacturing Practice”: “Good Manufacturing Practice” comprises guidelines for the quality assurance of production processes and environments that are used in the manufacture of pharmaceuticals, active ingredients, cosmetics, food and animal feed.

In order to optimally comply with these respective standards, companies need reliable quality assurance processes and - in practice - the corresponding quality controls.

How does quality control work in production?

Step 1
Define quality standards

So that the inspector knows what is to be inspected and how, the quality standards must first be defined as a quality assurance measure. To do this, quality assurance must

  • define measurable and evaluable quality criteria
  • define corrective measures in the event of deviations
  • record and formalize specifications, for example through standards or customer requirements
  • provide references, test plans or reference samples

Step 2
Production monitoring through regular quality controls

The next step involves continuous monitoring of the production processes from a quality perspective. For example, you can have visual inspections carried out by the worker using sensors or cameras. Quantitative tests and (performance) measurements - for example electrical tests, chemical analyses or stress tests - are also an effective means of quality control.

The aim of quality control is to identify deviations and errors by comparing the recorded results with the specified quality standards. If errors occur, you initiate appropriately defined measures to rectify them (rework, training, etc.).

Does everything fit? Then quality control releases the product as a good part.

Step 3
Documentation

Of course, quality control also includes recording the results. Among other things, the following are recorded in such a protocol

  • the name of the material or product
  • the batch designation, manufacturer and/or supplier if applicable
  • information on specifications and test procedures
  • information on the test equipment used
  • the test results (incl. observations, calculations, certificates of analysis)
  • the date and location of the test performed
  • the names of the persons carrying out the test
  • the names of the verifying persons, if applicable
  • the result in the form of a clear decision on approval or rejection

Step 4
Supporting continuous improvement processes

In this step, you move from quality control to quality improvement and use the findings from the audits to identify possible trends and promote continuous improvement processes. This in turn has a positive impact on your quality standards.

Digital quality control: technologies

Computer-aided quality for digital quality control

CAQ or QM software

There is a suitable solution for everything, including quality management. Computer-aided quality assurance (CAQ) or quality management software makes it easier to record and evaluate quality-related data. This data can in turn be used to derive conclusions for the further planning of quality assurance and quality control measures.

Worker guidance systems for digital quality control

Worker guidance systems

With a worker guidance system, you can guide employees digitally through inspection steps or complete inspection plans. As part of the digital work instruction, you specify standardized quality data and record collected or entered data directly in the system.

IIoT for digital quality control

Internet of Things (IoT)

The Internet of Things describes the networking of devices and systems - including in production. Networked sensors, cameras or control systems allow you to record data in real time and detect and rectify anomalies or quality deviations more quickly.

Machine learning and AI to support quality control

Artificial Intelligence (AI) und Machine Learning

Intelligent algorithms enable the centralized or decentralized evaluation of large data sets. They can predict possible errors or system failures that could affect the final quality of the product.

Advantages of digital quality control

Yes, we've already talked about the benefits of quality control above. But we have another bonus for you: digitized quality control offers further advantages:

Increased efficiency through quality controls

Increased efficiency

Digital systems document automatically, replace manual input and make input errors or subjective interpretations of errors obsolete.

Accessibility of data

Accessibility

If you map quality controls with a worker guidance system, for example, your employees have access to all required and relevant documents and information at all times.

Traceability through digital quality control

Traceability

Data and information are recorded digitally directly in the process and are therefore immediately available and traceable. This enables seamless traceability.

Consistent integration

Integration of peripheral systems

Digitization allows you to achieve consistency in your systems. You can easily exchange digitally recorded quality data across departments or along the supply chain.

Quality control for greater data security and compliance

Data security and compliance

Digital quality documentation can be digitally secured in a watertight manner – including access controls, encryption and back-ups.

Predictive Quality

Predictive Quality and CIP

The digital availability of data and its analyzability enable you to make predictions and continuously improve the quality of your processes and products.

Practical example: implementing digital quality control with weasl

For effective quality control, it is best to use a digital system - especially if you want to hand over inspection steps to your employees in production and assembly. Our worker guidance system weasl provides the perfect basis for this.

Easily implement test plans in weasl

Test plans as work instructions

With weasl, you can implement inspection plans as easy-to-understand, multimedia-supported step-by-step work instructions. You can use a role-rights system to define which inspections can be carried out by a worker and which can only be carried out by trained inspection personnel. In this way, you empower your workers to carry out worker self-inspection and strengthen their quality awareness.

Record quality data in weasl

Securely record quality data

You can easily validate quality-relevant entries with weasl by marking the corresponding input fields with color cues, for example. If an input value exceeds the tolerance range, the worker is informed by a red message text, for example. You can also prevent incorrect entries through standardization - for example, by only allowing measurements in defined numerical ranges and units.

Consistency incl. feedback function

Creating consistency

weasl communicates with your systems, tools and test equipment. If the required inspection tools are connected to weasl, your workers can automatically read out inspection data and transfer it to the system. Communication - for example in the event of queries or support requests - also takes place directly in the system thanks to the feedback function.

Automatic backup and logging of data

Document quality controls digitally

With weasl, you record and document all work steps, results and input values automatically. This prevents media breaks and the resulting errors and loss of time. At the end of a work or test plan, weasl automatically generates a log with all the data and information.

Conclusion

 

Without effectively established quality controls, any production process will struggle in the long term. Customers expect quality, lean production processes require error-free work and, last but not least, quality defects are also a cost driver.

Quality controls do not necessarily have to be a separate, extensive complex in your production. Simple but highly efficient measures can already be implemented as part of worker self-checks. With digital support such as a worker guidance system, you can make work easier for yourself and your employees by integrating quality inspections directly into your processes, recording data directly in digital form and ensuring automatic verification and documentation.

Implement quality control easily - with weasl

Enable your workers to carry out quality checks themselves in the production and assembly process. Record quality data digitally and establish effective quality assurance processes - with our weasl worker guidance system.

Experience for yourself what weasl can do - in our free showcase environment.

weasl Showcase Environment