13. The method of claim 10 , wherein the plurality of functionalities includes component model types belonging to a category of equations of motion models that include at least one simple variable mass model and at least one custom variable mass model.
10. A method comprising: selecting, using a computing device, a block in a block diagram model, where: the block represents a component model, and the component model has a plurality of functionalities; selecting, using the computing device, a first functionality from the plurality of functionalities; incorporating, using the computing device, the first functionality into the block diagram model using the block; saving the block diagram model that includes the first functionality in a memory; selecting, using the computing device, a second functionality from the plurality of functionalities; dynamically modifying, in the block diagram model, the block to indicate the selecting of the second functionality, the dynamically modifying: performed in response to the selecting the second functionality, and performed without removing the saved block diagram model from the memory; generating code for the block diagram model, the generating including: generating code for the block, the code for the block including: a first portion of code implementing the first functionality, and a second portion of code implementing the second functionality; and incorporating the second functionality into the block diagram model using the block, the incorporating including: conditionally executing the code for the block, where the conditionally executing: executes the second portion of the code without executing the first portion of the code.