Using UML for Modeling Procedural Legal Rules: Approach and a Study of Luxembourg’s Tax Law

Abstract

Abstract. Many laws, e.g., those concerning taxes and social benefits, need to be operationalized and implemented into public administration procedures and eGovernment applications. Where such operationalization is warranted, the legal frameworks that interpret the underlying laws are typically prescriptive, providing procedural rules for ensuring legal compliance. We propose a UML-based approach for modeling procedural legal rules. With help from legal experts, we investigate actual legal texts, identifying both the information needs and sources of complexity in the formalization of procedural legal rules. Building on this study, we develop a UML profile that enables more precise modeling of such legal rules. To be able to use logic-based tools for compliance analysis, we automatically transform models of procedural legal rules into the Object Constraint Language (OCL). We report on an application of our approach to Luxembourg's Income Tax Law providing initial evidence for the feasibility and usefulness of our approach.

A model-based framework for probabilistic simulation of legal policies

“…To this end, we developed in our previous work [5] a modeling methodology for specifying (procedural) legal policies. The modeling methodology produces two main outputs, as already described and illustrated in Fig.…”

“…2 shows a simplified policy model that calculates the tax deduction granted to a taxpayer for disability (invalidity). The stereotypes used in the model are from a previouslydeveloped UML profile [5]. This earlier profile extends activity diagrams with additional semantics for expressing policy models.…”

“…Our simulation framework leverages our previous work [5], where we developed a UML-based modeling methodology for specifying procedural policies (rules) and evaluated its feasibility and usefulness. We adapt this methodology for use in policy simulation.…”

“…Specifically, the contributions of this paper are as follows, with 2) and 3) being the main ones: 1) We augment our previously-developed methodology for policy modeling [5] so as to enable policy simulation. 2) We develop a UML profile to capture the probabilistic characteristics of a population.…”

“…This step yields two outputs: First, a domain model of the underlying legal context expressed as a UML class diagram, and second, for each policy, a policy model describing the realization of the policy using a specialized and restricted form of UML activity diagrams. This step has been already addressed in our previous work [5]. We briefly explain our background work in Section III-A and elaborate, in Section III-B, the extensions we have made to the work in order to support policy simulation.…”