  In this study, we interpret the notion of homotopy of morphisms in the
category of crossed modules in a category $\mathsf{C}$ of groups with
operations using the categorical equivalence between crossed modules and
internal categories in $\mathsf{C}$. Further, we characterize the derivations
of crossed modules in a category $\mathsf{C}$ of groups with operations and
obtain new crossed modules using regular derivations of old one.
