What Is Visual Inspection for Quality Control?

Visual inspection is a non-destructive testing technique that helps identify issues with assets or manufactured goods. While modern inspection techniques like vibration analysis continue to evolve, visual inspection remains one of the most cost-effective quality control methods of condition-based maintenance.

This guide explains what visual inspection is, why it’s valuable for maintenance professionals, and potential problems to be mindful of when using visual inspection as an asset-management or quality-control technique.

What Is a Visual Inspection?

Visual inspection is the process of inspecting physical assets such as machinery, pipe systems, and valves using the naked eye.

However, this type of inspection doesn’t necessarily only involve the inspector’s vision. Experienced professionals also can determine the presence of issues based on specific sounds that machines make or fumes from machines (such as gas in the case of a leak). Because there is no specific VI procedure to determine an issue, the effectiveness of visual inspection depends largely on an inspector’s experience.

While traditional VI is still in everyday use, modern VI now includes remote cameras and automated systems.

“New digital and analytics technologies make it easier for quality teams to access data from different sources and in various formats, without replacing existing systems.”

McKinsey

Visual Inspection (VI) Techniques

Visual inspection can cause reduced uptime. The traditional way of inspecting machines requires turning them off, which can impact production efficiency. It’s a reactive maintenance technique. These days, maintenance professionals rely on preventive maintenance techniques.

That said, VI is far from obsolete. Plus, technological improvements make visual inspections easier. For example, maintenance professionals can now use remote cameras, drones, and AI systems to inspect areas of equipment that are hard to reach or housed in locations with hazardous materials.

Modern visual inspection techniques can be broadly classified as:

• Remote visual inspection
• Automated visual inspection

Remote Visual Inspection (RVI)

Nowadays, VIs don’t need to be conducted at the asset’s location. Instead, inspectors can use high-quality cameras and other RVI tools to collect visual data remotely.

Generally, inspectors use RVI tools when the inspection area is either dangerous or difficult to reach, or both. For example, if the site you want to inspect is miles away from your current location, you can use remote cameras, a robot, or drones to inspect the site visually.

You can inspect the asset live as the camera streams directly to your current location, ensuring your safety even when inspecting a dangerous location like a mine shortly after blasting. It’s also possible to record footage on a camera if the location lacks network capabilities. Once you access the camera, you can review the recorded footage for potential issues.

Even if you live-stream the footage, be sure to record it. This allows other members, such as engineers and technicians, to view the footage later in case you need their opinion.

Automated Visual Inspection (AVI)

As with most industries, automation is useful for visual inspection. Automated visual inspection (AVI) relies on artificial intelligence (AI) to capture visual information through cameras.

AI works the same way with visual inspection systems as with anything. First, provide the algorithm with a sample of a well-manufactured product. You can also add a few defective product samples, so the algorithm learns what it needs to look for in a defective product.

Once implemented, the AVI system will inspect every product you manufacture. The system detects defects by capturing the product’s image from multiple angles and comparing it with the pictures of the well-manufactured sample you fed into the algorithm during setup.

Similar to how it works for quality control, you can use AVI to inspect equipment visually. AVI frees up time spent on repetitive tasks to let you focus on what’s essential: timely maintenance and repairs.

How to Standardize Visual Quality Control

You can standardize VIs the same way you deploy standard operating procedures (SOPs) and maintenance checklists for preventive maintenance. Standardization minimizes error and improves efficiency as the team performs the same steps over and over.

Although visual inspections can be simple, you can still standardize the process of inspecting more complex physical assets and manufactured goods.

Here is an example of a standardized process for visually inspecting physical assets:

• Create a list of physical assets
• Determine the frequency of inspecting assets
• Identify the specific parts of the equipment to be inspected
• If you find an issue, take action
• If equipment requires further inspection or repairs, create a maintenance checklist on your CMMS (Computer Maintenance Management System). Adding the checklist to a CMMS, especially a mobile CMMS, helps the technicians complete the work more efficiently.

Here is an example of how to standardize visual inspection for quality control (not to be confused with quality assurance, which, unlike quality control, is a preventive technique):

• Establish clear criteria for identifying a unit as defective
• Identify scenarios that warrant a more advanced VI system
• Determine who an inspector should consult when it’s difficult to determine if a product is defective with a visual inspection
• Establish guidelines on when to repair a defective product or discard it
• Create any other process-specific guidelines relevant to VI

How a CMMS Helps with Visual Inspection

A CMMS can make the visual inspection workflow a lot simpler. For example, a maintenance professional may want to check asset history for recent repairs when investigating a potential issue during a VI. If you use a CMMS, the maintenance professional will have real-time access to repair history, downtime history, and specific asset work orders.

If the VI reveals an issue, the maintenance professional can create a checklist or procedure using a CMMS to provide technicians easy access, helping them complete work orders faster. As technicians complete work orders, they can upload pictures of completed work using a mobile CMMS.

Try MaintainX using the 30-day free trial to see how a CMMS makes visual inspections easier.