Service Life Validation: Everything You Need to Know

Introduction

When developing or modifying a medical device, it’s not enough to prove that it works once. You must demonstrate that it continues to perform safely and effectively throughout its entire service life. That’s where service life validation comes in. 

Service life validation provides objective evidence that a device remains functional and safe under expected conditions of use, maintenance, and reprocessing. It’s a key part of medical device risk management and essential for demonstrating compliance with ISO 14971. 

What is Service Life Validation and Why Does it Matter?

A  medical device’s service life is generally considered to be the time between its first use and its retirement. ISO 14971, the medical device risk management standard, supports this definition but also asks manufacturers to consider how maintenance and repair may extend that period. The total duration that the device can remain safe and effective in use is the medical device’s true validated service life. 

What’s the Difference Between Service Life Testing and Life Cycle Testing?

Service life testing is best understood as an umbrella term covering any testing regime that replicates the total amount of stress a device might undergo throughout its service life. 

This might include the kind of repetitive testing that Ikea is famous for (during which a seat might be compressed 10,000 times to replicate someone sitting on it), or reprocessing life cycle testing  (during which a medical device might go through 100 cycles of cleaning, disinfection, and sterilisation). 

Life cycle testing focuses on a specific process (e.g., reprocessing), while service life validation evaluates the entire usable lifespan of the device. Generally, service life tests are not performed to destruction, so methods like Highly Accelerated Life Testing (also known as HALT, during which devices are exposed to stressors well beyond expected limits to rapidly determine weak points and to test fixes) do not come under the service life testing umbrella. Regardless of the test, when the total stress has been replicated, the device is assessed to see how it has been affected by the process.  

How Do You Design a Reliable Service Life Validation Study?

Developing an appropriate test method is vital. There are likely to be a lot of different stressors during a  medical device’s service life (normal usage, cleaning, disinfection, and sterilisation, maintenance, transport, storage, etc.). But it would be costly, challenging, and time consuming to simulate all of these at once. Most approaches select one or two stressors, depending on what sort of data is required, and replicate these.   

The goal is to replicate enough realistic stress to prove durability without overcomplicating the test. 

Why Bespoke Approach is Essential for Service Life Testing? 

No two devices work in exactly the same way. The impact of this, for many kinds of service life testing, is that the methods and apparatus must be customised to best simulate the intended usage and expected conditions of each device. It’s also important to consider which data points are relevant to the test, and how that might impact testing.    

What Does a Real-World Service Life Validation Test Look Like? 

In a previous study at Test Labs, six models of pump were evaluated for suitability as replacement parts in a disinfection system. Two tests were developed: 

1. Continuous operation testing. Pumps transferred disinfectant continuously, with minimal breaks, until the full service life of the system had been simulated. 
2. System simulation testing. Pumps were installed within a system of tanks to simulate the environment and pressures of the disinfection system. 

Performance was measured primarily by flow rate and operating temperature, recorded precisely at predefined intervals and monitored daily using built-in sensors. Each model was tracked for over 2,000 hours of operation to determine which models would make an appropriate replacement. 

Real-world service life validation combines continuous operation, environmental simulation, and precise measurement to verify long-term performance. 

When Should Manufacturers Conduct Service Life Validation?

There are many reasons why medical device’s service life validation might be necessary. Let’s look at three examples:   

Regulatory requirements 

When launching a new medical device. To meet medical device regulations, they now need to provide evidence for the service life they have reported in their risk management file. They have enough post-market evidence for their existing devices, but nothing for the new devices. Service life testing can rapidly provide that evidence.   

Replacement parts 

If a supplier changes or a component needs replacement. Manufacturers may conduct medical device’s service life testing at slightly above expected stress levels to ensure that the new component performs comparably and doesn’t reduce the device’s validated service life. 

Prototype devices 

The R&D wing of a manufacturer has developed a working prototype of a new medical device. Based on knowledge of the manufacturer’s existing devices, they have some concerns about the longevity of some components during the device’s service life, so they want the test to focus on these elements specifically.   

How Does Service Life Validation Support Regulatory Compliance and Risk Management?

Under ISO 14971, manufacturers must identify hazards, evaluate risks, and provide evidence that risks are controlled. Service life validation directly supports this by proving that medical  devices remain safe and effective over time, even under routine stress. 

It also strengthens a medical device’s risk management file, providing data that can be used to justify service intervals, maintenance schedules, and expected lifespan. 

Key Takeaways for Medical Device Manufacturers

• Service life validation confirms that a medical device performs safely and effectively throughout its intended lifespan. 
• It provides essential evidence for ISO 14971 compliance and regulatory submissions. 
• Customised test methods ensure relevance and reliability of results. 
• Service life validation supports design verification, supplier changes, and post-market confidence. 
• It strengthens both risk management and product reputation.