I make retail systems dependable beyond the successful demonstration: when a request is repeated, when a customer uses a keyboard and when a device approaches the end of support.
I began in application support with users who could describe what they had tried but not necessarily what the system had done. A screen could stop responding after the underlying action had succeeded. The person at the counter still needed an answer, and a confident instruction to try again could create a second problem. That early experience made me interested in the space between a technical event and the user's understanding of it. It also taught me that an application is part of a service carried by people, not a complete explanation of that service.
A successful response is only one part of a dependable service. I want the enterprise to understand what happens when the response is missing, the usual interaction is unavailable or the technology can no longer be supported.