This contribution presents a scheduling domain ontology, named SchedOnto, devised to tackle the formal specification of batch scheduling problems, as well as integration issues associated with the scheduling function. More specifically, this paper describes the ontological engineering approach that led to SchedOnto. The ontology characteristics along with its development process are presented, starting from the challenges that motivated the construction, the competency questions that defined the scope of the ontology, going afterwards through conceptualization and implementation stages, and finishing with some validation issues. SchedOnto relies on both, the ISA-88 and ISA-95 standards, which are well accepted in the industrial domain. After presenting SchedOnto, and its associated design process, this contribution addresses an example that shows the benefits of a formal representation of temporal aspects.