## 3 Research Design and TEDP-Methodology
### Categorization of the Use Cases with Their Requirements
This presented approach allows collecting and allocating requirements to the respective use cases. Product and manufacturing requirements are among the most important influencing variables for the EDP, which are, therefore, among the most important criteria for creating or tailoring an EDP [54; 55; 56; 57]. Through the conducted expert interview in Section 2, requirements and their importance were also surveyed. Accordingly, in the last and fifth step, the assessed requirements should be integrated into the reduction process. By doing this, a categorization of iMMS based on use cases in order to review and tailor pre-existing EDP, will be ensured. The main requirements for iMMS are specified in the following:  
* Production time;
* Reliability;
* Costs;
* Batch size. In order to ensure objectivity in the evaluation of the requirements and to avoid a central tendency error, a list with an explanation of the levels was created. This list is shown in Table 3. \begin{table}
\begin{tabular}{l c c} \hline \hline
**Paraphrased Use Cases** & **Reduction 1** & **Reduction 2** \\ \hline \hline  & **Abstraction Level** \\ \hline PUC x & Abstraction of PUC based on the derived attributes. & Abstraction of Reduction 1 based on the derived attributes. \\ \hline \hline \end{tabular}
\begin{tabular}{l} Farmold with micro-electronics for \\ permanent, non-invasive blood pressure \\ measurement at the ear. Therefore, it \\ must be biocompatible and comply with \\ Directive 90/385/EEC with risk class IIa. \\ This is helpful for stress-free long-term \\ measurements of blood pressure and, \\ thus, represents an enormous advance for \\ the diagnosis and therapy of patients \\ with cardiovascular diseases. \\ \hline... &... \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Qualitative content analysis of the PUC with the derived attributes—area of application, product and functions—with one example in Line 2. \begin{table}
\begin{tabular}{l l} \hline \hline
**List of the Main Requirements for iMMS** & **Explanation of the Assessment** \\ \hline Relevance of production time (pt) & High \(\leq\) 3 months, medium = 4–6 months, low = 7–12 months \\ \hline Relevance of reliability (r) & High = harm to people, medium= high financial damage of property, \\  & low = minor damage of property \\ \hline Relevance of costs (c) & Low = Costs of the MMS are a lot higher than the final product, \\  & medium = Costs of the MMS are more or less the same as the final \\  & product, high = Costs of the MMS are a lot less than the final product \\ \hline Planned batch sizes (bs) & Low = 1–20 pc, medium = 21–500 pc, high \(>\) 500 pc. \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Explanation of the assessment and list of the general requirements. With the steps shown above, characteristic product groups for iMMS can be created. Consequently, the EDP can be adapted and tailored to the created product groups. So, the methodology can be defined as follow: Qualitative content analysis + Assessments of the requirement = Product groups (see Table 3). Figure 3 shows the logical approach of the methodology. With this, product groups are characterized and can be traced back quickly and easily. These are, for example, that the costs and the batch size play an eminent role for this product group. The characteristics of the analyzed product groups are important influencing factors for the EDP. Therefore, it is important to create product groups for production processes and for tailoring of an EDP.