## 1 Introduction
Although the syntax and semantics of simulation languages such as Modelica are perfectly defined, there are not mechanisms for their extension or specialization in order to support domain-specific semantics. Alternatively, other general-purpose descriptive modeling languages, such as the Systems Modeling Language (SysML) [10], support mechanisms for the development and use of domain-specific modeling languages (DSML), which detail the semantics for a specific domain. Specifically, SysML enables the definition of profiles that extend the language, adding stereotypes and details to the specific semantics through Object Constraint Language (OCL) expressions [11]. These OCL rules, defined in the profile level, can be validated in those constructions of the user model where stereotypes are applied by checking if the rule condition is satisfied through queries without side effects. SysML has usually been linked to models with a high abstraction, far from the correction adopted in typical mechanical engineering models (such as CAD). This is the main reason for the limited adoption of SysML in the field of mechanical engineering [12]. Some works in recent years have explored the integration of SysML models with other domain-specific models, as in [13] or [14], or the mapping of domain-specific models into a common generic system model supported by SysML [15]. Other works are focused on the definition of SysML profiles and, specifically in the domain of mechanical engineering, several proposals such as SysMLMatchronics [16], SysML4 FMArch [17], GERTRUDE [18], or \"C&C-M for SysML\" [19; 20] have been published. However, these works deal with embodiment from the conceptual or functional perspective, but we found no works that used SysML (or SysML profiles) capabilities to model tolerances and support simulation models for geometric variability analysis, an issue that is explored in this work. The previous review and comments raise the following research questions:  
RQ1. Does SysML have enough capability to support a tolerance analysis using the TTRS-based modeling of nominal and deviated geometries? RQ2. What OCL rules are necessary for assuring the consistency between models according to tolerance analysis semantics? Are OCL rules sufficient to assure consistency?RQ3. How can profile architecture and defined stereotypes ease subsequent model transformations from SysML to other analysis languages, such as Modelica? RQ4. What are the necessary steps (procedure) to support analysis modeling? How is this procedure integrated with other previous tasks, corresponding to the system functional and logical architecture modeling? To explore these issues, our research group is developing the framework illustrated in Figure 1; it is based on a SysML central model (optionally constructed from other CAx models) and the use of model transformations. In this framework, two goals guide the use of SysML profiles: (a) consistency assurance between models according to specific domain semantics (e.g., SysML4 TA) and (b) concept identification to facilitate model-to-model and model-to-text transformations (e.g., \"SysML4 TA for Modelica\"). This paper is focused on the first goal, specifically, on the definition and development of the SysML for Tolerance Analysis (SysML4 TA) profile. The theoretical framework of this proposal was established from a literature review of previous proposals focused on two types of models. On the one hand, models that support the specification/design of assemblies were reviewed, including the metamodels proposed by the NIST (core product model (CPM) [21] and the Open Assembly Model (OAM) [22]) or additional proposals based on them (such as Modified OAM [23]). These metamodels provide a standard representation of assemblies, facilitating interoperability in CAx environments. On the other hand, we also considered models that facilitate the principle solution by, e.g., supporting the modeling of active surfaces and their relationships.