In this tutorial, we compare OWL-DL reasoning and Petri net analysis for validating refinement and grounding of business processes. (1) Process refinement: Like in software engineering, the implementation of a business process involves different interacting roles, such as business expert, analyst, process architect, and developer. Each role designs and refines different abstractions of the process until it is sufficiently refined. It is important to verify that the process models of the different abstractions are consistent. (2) Process grounding: A sufficiently refined process has to be mapped on existing IT systems. Ideally, IT systems consist of components with a semantic annotation of their behavior. The most specific process must respect all IT systems' behaviors. Formally capturing process semantics enables to check automatically for consistent process refinement and grounding. The classic application of semantic techniques in the area of static models is well understood. The analysis of business processes deals with dynamics. Modeling dynamics is a challenge for current approaches of semantic Web services. We compare advantages and shortcomings of Petri net analysis and description logic (DL) reasoning for refinement and grounding validation.