**1. Introduction**

The progress of manufacturing technologies tends to astonish observers. For example, at Leibniz University Hannover, the Collaborative Research Center (CRC) 1153, which is funded by the German research association, explores process chains for tailored forming [1]. Here, semi-finished hybrid workpieces, consisting of two different materials like steel and aluminum, are processed by forming, heat treatment and cutting technologies to produce high-performance multi-material parts [2,3].

Ashby and Cebon have shown that for special purposes, a multi-material design achieves superior performance than a conventional design [4]. Thinking of structural components like wheel carriers, rocker levers, or even pinion shafts, areas where high stiffness and wear resistance are needed can be made from steel, all other areas are made from aluminum [5]. So, from a design point of view, a new degree of freedom is introduced, which is the material distribution within the multi-material part. What initially appears to be an interesting avenue for leveraging even more efficiency of such parts results in higher complexity for the design since the material distribution generally influences the mechanical properties [6–9].

However, more than this, the complexity rises also from the manufacturing point of view [10]. The tailored forming technology requires production lines where many manufacturing steps follow each other, whose processes are linked and therefore precisely coordinated [11]. Setting up and running in a new product variant result in large efforts, especially when process windows need to be (re-)evaluated and the quality of semi-finished materials varies [12,13]. Thus, it is necessary for the designer to consider the available capabilities of manufacturing as early as possible since they restrict the possible solution space of the part geometry [14]. Examples, therefore, range from simple manufacturing restrictions like maximum traveling distances or hardening depths [15], over appropriate tolerances of dimensions, form and positioning to the consideration of design guidelines, as is discussed today as Design for Excellence (DfX) [16,17]. Here it also must be considered that both materials of a tailored forming part may differ in their processing, i.e., forming temperatures, cutting speed, etc., [18,19].

In order to avoid iterations during design, computer-aided engineering environments (CAEE) support the designer in making the right decisions, checking the design with respect to the solution space and finding the optimum between requirement fulfillment, capabilities and resulting production costs [15,20,21]. On the one hand, they include all necessary synthesis and analysis tools for a design task [5,22–24]. On the other hand, e.g., artificial intelligence technologies offer the possibility to process data from production, find patterns and formalize new manufacturing knowledge automatically [25–27]. Thus, such CAEE serve as a central information hub for all experts that are involved in the according to the design process [28–30].

Within the scope of this work, a CAEE is set up to reduce the uncertainties in the development of tailored forming components and to help ensure that they are adapted as optimally as possible to the respective use case. The CAEE has different tools that are used in different phases of the product development process. The manufacturing and process knowledge needed for the development is provided by the subprojects of the CRC 1153. Accordingly, the CAEE offers the possibility to extend the underlying knowledge base with new insights gained in the CRC 1153 and delivers rough as well as detailed designs of tailored forming components accordingly. Special consideration is given to the material distribution in the component as well as the implementation of the applicable manufacturing restrictions. The article is structured as follows. The second Section deals with the state of the art on the relevant topics of tailored forming, design theory and knowledge-based systems. Section 3.1 presents the methods and tools of the CAEE with which rough and detailed designs are implemented. In the following Section 4 these are implemented by means of corresponding examples. In the last two Sections 5 and 6 the contribution is summarized and a conclusion and an outlook to further research projects are given.
