Boßelmann, Steve2023-05-242023-05-242023http://hdl.handle.net/2003/4137510.17877/DE290R-23218Language-Driven Engineering (LDE) is a means to model-driven software development by creating Integrated Modeling Environments (IMEs) with Domain/Purpose-Specific Languages (PSLs), each tailored towards a specific aspect of the respective system to be modeled, thereby taking the specific needs of developers and other stakeholders into account. Combined with the powerful potential of full code generation, these IMEs can generate complete executable software applications from descriptive models. As these products themselves may again be IMEs, this approach leads to LDE Ecosystems of modeling environments with meta-level dependencies. This thesis describes new challenges emerging from changes that affect single components, multiple parts or even the whole LDE ecosystem. From a top-down perspective, this thesis discusses the necessary support by language definition technology to ensure that corresponding IMEs can be validated, generated and tested on demand. From a bottom-up perspective, the formulation of change requests, their upwards propagation and generalization is presented. Finally, the imposed cross-project knowledge sharing and transfer is motivated, fostering interdisciplinary teamwork and cooperation. Based on multifaceted contributions to full-blown projects on different meta-levels of an exemplary LDE ecosystem, this thesis presents specific challenges in creating and continuously evolving LDE ecosystems and deduces a concept of PUTD effects to systematically address various dynamics and appropriate actions to manage both product-level requests that propagate upwards in the meta-level hierarchy as well as the downward propagation of changes to ensure product quality and adequate migration of modeled artifacts along the dependency paths. Finally, the effect of language-driven modeling on the increasingly blurred line between building and using software applications is illustrated to emphasize that the distinction between programming and modeling becomes a mere matter of perspective.enLanguage-Driven Engineering (LDE)Domain-Specific Language (DSL)004Evolution of ecosystems for Language-Driven Engineeringdoctoral thesisDomänenspezifische SpracheModellgetriebene Entwicklung