In the data space scenarios addressed by this paper, there are two roles that interact: 
\begin{itemize}
	\item A data provider, such as a data holder (\cite{eu-data-act}), that publishes a dataset together with an ODRL policy stating the permitted and forbidden actions, the conditions under which they apply, and any additional obligations on the consumer.
	\item A data consumer, that designs a Data Processing Workflow (DPW) that includes processing of the provider’s dataset, thereby requiring adherence to the constraints set forth by the provider.
\end{itemize}

In this context, interoperability issues may emerge, due to the use of different semantic models, as well as conflicts between consumer's processing intentions and provider's constraints regarding the use of data. Such conflicts may not only concern contradictory rules, but also variations of similar authorisation contexts, such as different data encryption status, or contextual attributes; to this end, rules correlation should not concern their syntactic comparison, but rather their semantic analysis.

Therefore, the focus of this paper is to foster interoperability and collaboration among data providers and consumers, by providing three mechanisms:

\begin{itemize}
	\item An ontology-import mechanism that automatically aligns organisational information models with standard vocabularies such as DPV and ODRL. 
	\item A bi-directional ODRL adaptor that translates ODRL structures into semantic attribute-based access and usage control rules and vice versa. 
	\item An enhanced Policy Decision Point (PDP) that is able to identify conflicts in complex settings and propose appropriate resolutions.
\end{itemize}

These mechanisms have been incorporated to goodFlows, a semantic framework devised for the specification of access and usage policies and workflows over a common information model, and the verification and re-engineering of workflows on the basis of the policies. The results presented in this paper have been mainly developed in the context of the Horizon Europe UPCAST project\footnote{\url{https://www.upcast-project.eu/}}.

The rest of the paper is outlined as follows. Section~\ref{sec:goodFlows} provides some background information on goodFlows. In Section~\ref{sec:alignment-with-ODRL-and-DPV}, the two alignment mechanisms are described, fostering interoperability at the information and policy model levels. Section~\ref{sec:conflict-resolution} delves into the process of resolving conflicts between data consumer’s processing intentions and data provider’s constraints. Finally, Section~\ref{sec:conclusions} provides some concluding remarks.
