Answer:
Yes it is ok
Step-by-step explanation:
This usually depends on what the engineer is trying to accomplish or learn. For example, if the engineer is simply trying to understand how the architecture floats or cuts through the water then he does not need to model the engines or other unnecessary characteristics. On the other hand, if the engineer wants to understand how the engine provides power to the entire ship then he would need to model the engine and all the connected parts but not the outer exterior of the ship. Therefore, it is ok that he did not model the ship completely as long as it provides the information needed.