Why Model?

A model of a system is an abstraction that represents aspects of the system in a way that can be analyzed, but which is much faster, easier and cheaper to create than the entire system. When architects create a mock-up model of a new building using foam core board and hot glue, they are doing it to show off their creation, but also to work out details that aren’t apparent from a flat drawing. When systems engineers spend time thinking about how a system will be used and documenting use cases, they are likely to discover new things about the needed system. When designers create a first prototype using slow 3D printing, it might take hours to produce a single part, but what can be learned is well worth the wait compared to the risk of manufacturing a batch of 500 only to find an issue that forces the scrapping of the entire batch.

When a descriptive model is created using the SysML modeling language to precisely describe the interfaces between a system and other systems with which it will interact, the model enables everyone to agree on the way these interfaces will work, before time is wasted building systems that end up not connecting correctly. It is scarcely possible to overestimate the time and work that can be saved by employing this modern version of measure twice, cut once. Modeling enables the team to do it right the first time because, at the risk of piling on the aphorisms, there may not be time to do it right, but there is always time to do it over.?