Some times ago I faced the problem with the low quality of the customer’s demonstration. When we try to present our application for the wider audience, we have problems with doing some basic scenarios again and again. We thought that we well tested this functionality. We were using it every day, and everybody in our team was checking it after each change. However, the application functionality still evolving. Moreover, any modification of the code may result in changing final functionality. Because of many changes before demo we can’t test it enough to be 100% sure that everything works fine.