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What it's about

In this article, we look at the opportunities and risks of worker self-inspection and give you 7 tips for a successful usage.

What is a Self Inspection and Who does it?

An assembly process often consists of several sub-steps that are carried out by different employees one after the other. After carrying out their assembly step, each employee checks the quality of the workpiece before it goes on to further processing. This self-contained quality control is called worker self-inspection.

Some time ago, the German Society for Quality (DGQ) asked 150 quality assurance experts about their quality philosophy as part of a study. Back in 2013, the most frequently cited answer was worker self-inspection, at 73.1 %. And the trend has continued.

What is the importance of self inspection?

Worker self-inspection offers three central opportunities. In addition to early identification of findings, error prevention plays an important role. In addition, this quality philosophy can contribute to increased employee loyalty.

Early defect identification and response opportunity

Let’s first take a look at assembly without intermediate inspection: Assuming that a defect already happens to the employee in the first process step and the workpiece nevertheless passes through the complete assembly process – a process that is also often called scrap refinement. In this case, the defect may not be discovered until the final inspection and rework may be required. It may even be necessary to disassemble the entire machine to correct the defect. In the worst case, defects that occur very early in the assembly process are not detected at all in the final inspection. The customer then receives a product that does not meet his quality expectations and a complaint is made. However, if a worker inspects his own work after completing his task, the reaction time is reduced immensely. Errors and defects are detected immediately and can possibly be rectified directly by the inspecting employee before the workpiece is processed further. Early defect detection saves costs and, in particular, time.

Defect prevention

On the one hand, worker self-inspection increases the quality awareness of employees. This is because it is now up to the worker to discover his own defects. As a result, he may work even more conscientiously in the assembly process, thus resulting in fewer errors. The second opportunity for error prevention lies in documentation. The documentation of the quality inspection can simply be linked to an assembly instruction. The advantage is that workers always carry out assembly on the basis of an instruction instead of relying on their own process knowledge – as is often the case with experienced assemblers.

Increasing motivation

Workers are given full responsibility for their sub-process and thus also for the quality of their work. Factors such as empowerment and job enrichment contribute to employee motivation. In times of a shortage of skilled workers, this is an enormously important factor in employee retention.

The risks of worker self-inspection

Worker self-inspection also involves risks. However, these can be mitigated by appropriate countermeasures.

Inadequate quality inspection

There is no longer any separation between the inspector and the assembler, which can lead to conflicts of interest. The employee has assembled the workpiece himself and may be convinced that he has not made a mistake. The employee may confirm the quality in the quality documentation without having inspected it separately. Measures are needed here to ensure that quality checks are carried out carefully.

Increasing complexity

Workers take on additional tasks and may have to deal with increasing complexity. To carry out the quality check, the worker must occasionally interrupt the assembly process, and in particular the complexity of the content, e.g. of electrical tests, can present him with new challenges. Added to this is the necessary documentation of the inspection.

Worker self-inspection: efficiency lever or quality risk?

Manufacturing companies can benefit from the introduction of worker self-inspection. Early defect detection and defect prevention by the worker increase quality while reducing costs for rework and complaints. If workers are also motivated by their new responsibilities, they are less likely to feel overwhelmed by the increasing complexity. To turn self-inspection into an efficiency lever, we’ve put together 7 tips to help you keep the risks low and take full advantage of the opportunities.

7 tips for a successful worker self-inspection

1. Introduce self-testing for complex products

Use worker self-inspection for complex products with a large vertical range of manufacture. This is because, especially for manufacturing-intensive products, reworking due to a defect discovered late involves high costs.

2. Invest in training

Worker self-inspection cannot be introduced without additional effort. In an initial training course, you should provide your employees with the necessary knowledge and skills to operate the measuring equipment in order to ensure proper testing. You should also use this opportunity to motivate your employees and create an understanding of the importance of quality inspection.

3. Delegate simple inspections to workers

Workers may lack the necessary experience to perform complex tests. For example, electrical tests that measure voltages or resistances should only be performed by trained professionals. On the other hand, simple test points, for example simple mechanical and visual tests, which are confirmed with OK and NOK checks, are suitable for self-testing.

4. Use visual elements as reference

Visual elements increase the quality of inspection processes. Provide pictures and videos for good and bad parts. Workers can use these as a reference for their own checks. This way, you can be sure that your workers will reliably determine if they have made a mistake in the assembly of the workpiece.

5. Performing final inspections

Worker self-inspections are not a substitute for inspection by a quality manager. Since workers primarily perform simple inspections, it is imperative that a final inspection is performed by a trained quality inspector after the workpiece is completed. This will also prevent the self-inspection from not being carried out carefully due to a lack of a control organ.

6. Perform analyses of the data

The typically straightforward data structure of a self-inspection allows you to easily perform analyses. Perform continuous analyses at each manufacturing step with self-inspection and use the findings to derive measures for process optimization. If, for example, you notice that defects are repeatedly not detected during a test step, this could be an indication that the worker has not understood the test correctly.

7. Checking the implementation of the concept

A review of the effectiveness of the concept should take place on a regular basis. Check not only whether more defects are detected or whether the number of complaints decreases, but also the implementation of the self-checks. Internal audits are suitable for this purpose, for example.


Worker self-inspection can be a powerful tool for increasing efficiency. Used correctly, self-inspection leads to less rework, higher quality and motivated employees. Find out how to provide your employees with intuitive inspection instructions with integrated inspection functions such as OK/NOK, comment function or image feedback and how to make the resulting data easy to evaluate in our e-paper Checklist 4.0.

Checklist 4.0

With digital checklists, you increase efficiency and make better decisions. Read in our whitepaper how our software solution can help you!

Moritz Stern

Head of Strategy & Marketing moritz.stern@operations1.com

About the author

Moritz Stern is head of strategy and marketing at Operations1. Before joining Operations1, Moritz worked at Strategy&, PwC’s strategy consultancy. Here he advised clients from the operations environment around the globe on strategic issues. Previously, Moritz worked for Alstom Power, Merck KGaA and Arthur D. Little. Moritz holds a degree in industrial engineering (M. Sc.).


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