I think modeling can be used in 2 context at least:
1. For documentation purposes.. If someone need to understand a computerized system and yet they weren’t involved with the development of the system, then reading documentation containing description of systems in the form of modeling diagrams would make them faster to understand the system. In contrast if they have to read the program codes, it would take more time to understand.
2. Models can be used to automatically generate programming codes and therefore, automatically generate a functional system. Can skip programming, only need to model. I think there are already tools like this.