A key aspect in creating models of production systems with the use of model-based systems engineering (MBSE) lies in the description of system functions. These functions shouldbe described in a clear and standardized manner.The VDI/VDE 3682 standard for Formalised Process De-scription (FPD) provides a simple and easily understandable representation of processes. These processes can be conceptualized as functions within the system model, making the FPD particularly well-suited for the standardized representation ofthe required functions. Hence, this contribution focuses on thedevelopment of a Domain-Specific Modeling Language(DSML) that facilitates the integration of VDI/VDE 3682 into the Systems Modeling Language (SysML). The presented approach not onlyextends classical SysML with domain-specific requirements but also facilitates model verification through constraints modeled in Object Constraint Language (OCL). Additionally, it enables automatic serialization of process descriptions into the Extensible Markup Language (XML) using the Velocity Template Language (VTL). This serialization enables the use of process modeling in applications outside of MBSE. The approach was validated using an collar screwing use case in the major component assembly in aircraft production.