What does reliability mean in computer science? Speaking about an application, how can we say it is reliable? I don't know if there is a shared opinion but mine has maturated after a scary situation.

Some years ago, on my previous workplace, we created a huge file with a very powerful and even more expensive third party software. But some seconds after having pressed the save button, the software crashed. Panic. We searched for the saved file and we found it. Don't panic. So we restarted the powerful-and-expensive-third-party-software to reopen the file but it failed. We tried several times even on other PCs without success. The (binary and proprietary) file seemed to be corrupted. Okay, panic!

Fortunately we also owned a license of a similar software, much less powerful and much cheaper (about twenty times cheaper). We had nothing to lose so we tried to open the file with this cheap software and... it worked! All our job was there. So we saved the file with a different name in the cheap software and eventually we were able to open it with the expensive software.

After that incident I have a clear idea of what reliability means when speaking about applications. And you?

Image created with GIFYouTube. Scene taken from movie "Airplane II: The Sequel".