This paper aims to explore processes and their identity with a focus on the upper ontology Basic Formal Ontology (BFO). We begin with a classification based on two basic classes of changes of independent continuants: changes with respect to a single specifically dependent continuant thereof or with respect to the spatial region that its parts occupy. We accordingly distinguish two kinds of simple processes: specifically dependent continuant changes and spatial changes. Next, we investigate a compositional approach to the identity of processes: the identity of any process is determined by the identity of the simple processes that compose them. Then, we consider a causal approach to the identity of processes with recourse to a dispositional view of processes according to which any process is a realization of some disposition. We also examine assumptions on which these two approaches to the identity of processes are based.