With customer care becoming an increasingly important part of a company's strategy, contact centers are being increasingly scrutinized as a place where a company may be letting recurring revenue fall through the cracks.
Although companies may work on improving agent interaction or processes to avoid long holds. The fact is that your contact center can easily be taken out of operation if it encounters a surge of traffic it hasn't been tested against.
As it turns out, most organizations are operating contact center systems that have never been truly tested under load.
"In our experience, the first stress test you do - you fail. And that's by our customer's standards, not our standards," Sam Melvin, Co-Founder of Voxology, explained.
This alarming statistic underscores the critical importance of comprehensive stress testing as part of your operational resilience strategy.
But what exactly does effective stress testing entail, and how can organizations implement it to ensure their systems remain robust even during the most demanding periods?
Key Components and Common Vulnerabilities of Stress Testing
Effective stress testing requires a structured approach that targets specific components of your contact center infrastructure.
According to Melvin, comprehensive stress testing should address three critical areas, each with its own common vulnerabilities and failure points.
"If you want to break it down, there's three broad components that are generally worth testing," Melvin explained.
"The first would be to test your carrier’s capacity. Are you getting from your carrier the channels that you're paying for?"
This first layer focuses on carrier capacity, a frequently overlooked vulnerability in contact center infrastructures.
"It's not uncommon to be paying for more channels than you’re actually getting," Melvin said.
This discrepancy often goes undetected during normal operations but can become apparent during peak periods.
"We'll load up a test and you can see it - we'll get it to 500 channels and every call after starts getting a busy signal," he explained.
The second critical component involves testing your Interactive Voice Response (IVR) system's ability to handle incoming call volume.
"The second test is to make sure your IVR is getting you the calls per second that you're paying for," Melvin continued.
"So whether that's a cloud system or something you've built and host on your own, the question is, are you able to handle a surge of calls at the rate that you expect?"
The third component dives deeper into the actual customer experience within your contact center system.
"In a third test, you can drill deeper into the IVR and test the actual call flows, the queues, the data dips that happen where you put your account number in before you get to an agent," Melvin explained.
This layer examines how well your underlying databases and application infrastructure perform when handling authentication, routing, and other data-intensive operations at scale.
At this layer, stress testing often uncovers processing bottlenecks that only appear under heavy load. "Your carrier and IVR are handling the calls per second, but once you get up to 1,000 channels, you're starting to experience audio issues, sometimes broadly, because your network is not handling it very well," Melvin noted.
These networking issues between system components can be particularly difficult to diagnose without comprehensive stress testing.
Here's where one of the most concerning vulnerabilities often appears: unexpected disconnects.
"One of the most common issues we detect after the call gets connected, is an unexpected disconnect," Melvin said.
"The company's IVR is talking to you, and the call just drops."
These issues typically stem from interdependent system components that may function correctly in isolation but fail when working together under load.
"While testing individual components is important, testing your entire UC/CC stack is critical," Melvin emphasized.
"You can perform load tests on all of them, and they can perform well. For instance, the individual components may all pass a load test, but when you put them together, for some reason, the network between these two can't hold up."
By systematically testing these three layers and understanding their common vulnerabilities, organizations can identify and address potential failure points before they impact customer experience during peak periods.
Creating Realistic Test Scenarios to Stress Test
One of the most challenging aspects of effective stress testing is designing scenarios that accurately reflect real-world conditions your contact center might face.
Generic load tests often fail to uncover the specific breaking points in your system that could lead to customer experience failures. To accurately address this, tests should aim to mimic real world situations.
"The way we replicate this real world is we test from the outside in," Melvin explained.
"We will place synthetic calls into that phone number. This means we can test everything through the PSTN, but also a number of stress tests mostly want to focus on their own infrastructure."
This approach of testing from the "outside in" is crucial for gaining an accurate picture of how your systems will perform under real-world conditions.
