option, is to start with the root OPD (SD) and go down the hierarchy. Here we reach the second parameter (that is independent of the first one), which is the required number of OPD levels (k) to go down the hierarchy. In order to give the user control over the level of abstraction, the diagrams are generated up to k levels down the hierarchy. Each level will result in the generation of an additional Activity Diagram, which is a child activity (subdiagram) contained in the enclosing higher-level activity. The default setting for this option is "all levels down" (i.e., "k = ∞"). See also Formal ontology Process ontology Ontology language Upper ontology References External links Object-Process Methodology and Its Application to the Visual Semantic Web, presentation by Dov Dori, 2003. Some Features of the Technical Language of Navya-Nyāya Formalizing the Conceptual Modeling Thought Process to Benefit Engineers and Scientists., presentation by Dov Dori, 2015. Formalizing the Conceptual Modeling Thought Process to Benefit Engineers and Scientists US Patent US7099809B2 on conversion of OPD to and from text formats Data modeling languages Specification languages Workflow languages Project management techniques Systems engineering Modeling languages