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Rainwater harvesting attracts growing interest from the field of municipal planning. When considering a rainwater harvesting system as a design object, questions include whether the system is designed for a single property or for a local water network serving multiple properties, what allows for the inclusion of buffer tanks and resource balancing among participants in the network, how to size the tanks, and how robust the system is in the face of changing demands. Knowledge-based engineering provides methods and a tool set for such planning objects. For this article, the authors applied techniques based on model-based and resource-based configuration and Bayesian decision networks to propose a knowledge-based engineering system for residential, networked rainwater harvesting and distribution systems. This enables designers to investigate the effects of different catchment areas, adjust or minimize the storage tank sizes in the grid and evaluate their effect on the individual harvest and the exchange with a central network buffer, evaluate the demands within a neighborhood based on a detailed consumer model also over time, and test the sensitivities of the single sinks and sources to the water grid. For urban planners, this offers the possibility, for example, to make design obligations for housing construction or for the refurbishment of settlements.

In the event of damage to additively manufactured components whose shape cannot be produced by machining, an additive repair can potentially be not only ecologically but also ecologically more favorable than the production of a new component. In addition, a number of hurdles that otherwise often impede the use of additive repair, e.g. the availability of the material of the damaged component for the additive process, are eliminated. As far as the authors are aware, this publication is the first to present a process for the additive refurbishment of additively manufactured components using the example of a wheel carrier. In this context, the possibility of increasing the fatigue strength of a structural component in refurbishment is discussed for the first time. To increase the fatigue strength of the wheel carrier, the chosen approach is to integrate the effect of particle damping into the component. Particularly in the case of components subjected to bending stresses, the effect of particle damping can be integrated into the component's interior without having to accept a significant loss of strength.

One of the arguments against an increased use of repair is that, due to the constantly growing progress, an often already outdated component would be restored. However, refurbishment also allows a component to be modified in order to upgrade it to the state of the art or to adapt it to changed requirements. Many existing approaches regarding Design for Upgradeability are based on a modular product architecture. In these approaches, however, only the upgradeability of a product is considered through the exchange of components. Nevertheless, the exchange and improvement of individual component regions within a refurbishment has already been successfully carried out using additive processes. In this paper, a general method is presented to support the reengineering process, which is necessary to refurbish and upgrade a damaged component. In order to identify which areas can be replaced in the closed system of a component, the systematics of the modular product architecture are used. This allows dependencies between functions and component regions to be identified. Thus, it possible to determine which functions can be integrated into the intended component.

The main design activity in engineering practice is to adapt existing designs or to create variants of existing products to new demands, which require a robust model against both parametric and topological changes. To design such a kind of model becomes a big challenge, especially in the development of structural components due to the number of load application points, variable load cases and restrictions from manufacturing technologies. Thus, the generative parametric design approach is applied to generating high dynamic product models, allowing them to be adjusted for changes feasibly.

Boundaries between products and services vanish and companies increasingly offer hybrid solutions known as Product Service Systems (PSS). Thereby, a holistic view that includes both the product and service parts must be taken. This paper presents a discrete-event simulation of a PSS as a method for the specification of the product part. Besides product and service, the application scenario and the decision-making are also modeled. Based on the results for a case study, the customer requirements could be guaranteed as the essential product specifications were optimized to minimize total costs.

For an optimal preparation of mechanical engineering students for their future work life, the use of problem-based methods in design teaching is investigated. Therefore an intelligent tutoring system for computer aided design education will be developed, which can automatically evaluate computer aided design models of design students. A knowledge-based engineering system will be used to assistance the design students in the execution of design tasks. Using a practice-oriented example, the application and the advantages for teaching will be verified and discussed.

During product development, many decisions have to be made which affect the entire product life cycle. Especially in early phases in product development these decisions are subject to uncertainties when involving customer specific requirements. To support the designer in developing robust products that are insensitive to uncertainty, this paper compares two opposing approaches for modeling and assessing uncertainties: an explicit method in form of a Bayesian decision network with utility functions and an implicit method in form of a robust numerical optimization with sampling of a model-based product representation. Hence, a quantitative and qualitative comparison is provided regarding the modeling expense and the usability in early design stages. Regarding the integration into the product development process we propose a combination of the two approaches as complementary tools.

In order to develop Product Service Systems (PSS), a holistic view on the system and a coequal development of service and product parts is necessary. Particularly for the beginning of the development of PSS, existing approaches show lacks and start with vague defined initial phases. This leads to inadequate methodological support for the consistent design of the overall system and simultaneous elaboration of the requirements down to the parameters of individual components. Therefore, a procedure is required that completely maps the PSS and enables detailed development for relevant individual areas, taking into account existing constraints. At the beginning of the development a model is necessary, which first defines the system boundaries of the PSS and maps the performance and control flows of the system. In addition, the integration of further actors into the PSS must be made possible. This paper presents an approach that uses System Dynamics (SD) to design a PSS. With this approach, the representation of the system is initially possible at a high level of abstraction, whereby the representation can be further refined and detailed. Parallel to this, a preliminary design for planning and controlling media flows can be carried out from the first system representation and further detailed parallel to the system representation. An essential advantage is that the detailing can also only be carried out for individual areas, which can be displayed in sub-models, but can also be reintegrated into the overall representation. The sub-models can be implemented function-specifically on the basis of resources and competencies of individual actors. For system-relevant areas, planning and design can be concretized in the sub-models (which can be realized by products as well as services) down to the lowest hierarchy level. This can take place up to the definition of individual physical component parameters and has thus up to the phase of the elaboration effects on the development of the parts. In return, the effects of changes in system-relevant parameters on the overall system can also be examined. For the PSS, a model is built in which system-determining functions and principles are represented and developed. The model is constructed in such a way that non-system-determining functions and principles are defined as variables or black boxes. Requirements and parameters are derived from this system development. These are used for the further development steps in the development process. Depending on whether it concerns system-relevant areas or not, the entry into the development process takes place later in the elaboration phase (e.g. in the area of detailed design) or partly earlier in the concept phase (e.g. function development). It is also possible to enter an early phase in the development process of the individual parts, accompanied by already defined functions, sub-functions or parameters that must not be changed in the course of development. With this approach a holistic development of the system with all product and service parts as well as their connections and dependencies is possible.