## 3 Use Case: Planning Tool for Micro Assembly
### Implementation  
For the implementation of the presented method, many variants were possible. To foster the accessibility and the ease of use, a web based single-page application was proposed for the assembly sequence modeling. This application is called Configurator. Users can work with such an application without the need for installing a dedicated software. It runs on every platform that supports a modern web browser. A web application can be developed by using existent frameworks like Angular, Ember, React, or Vue.js. For Configurator, Angular was used. Angular is an open-source web application framework. It was developed by Google and built upon Node.js. Node.js is an open-source JavaScript library, enabling server-side executed JavaScript web applications. Node.js also has the node package manager (npm) that allows the easy installation of Angular and other packages, as well as their dependencies. An Angular application development is mainly based on components and services. Services are reusable TypeScript modules that can be imported and executed in different components. Components determine what happens on a patch of screen called a view [28]. They are written in TypeScript and offer classes, methods, loops, and more to enable a developer to build a dynamic application. The actual website, which is displayed in the browser, is realized with an accompanying template of the view. It defines a structure via a Hypertext Markup Language (HTML) file. This HTML file can be styled using different styling sheets. The most common and used with Configurator is the Cascade Style Sheet (CSS). The connection between this structure's HTML file and the TypeScript component was implemented via data bindings of variables. If the user changes something on the screen and therefore changes a defined variable in the HTML implementation, the Angular framework as a controller will automatically rerun the accompanying component logic and recalculate all involved variables. Through the data binding, this may re-affect the HTML structure and lead to a reloading of the website, displaying new or changed content. With Angular, Material, an adaption of Google's Material Design philosophy, is available and used in Configurator. It can be installed using the npm. Angular Material offers versatile possibilities for dynamic user interface elements like buttons, forms, dialogs, or drop-down menus. Nevertheless, the modeling of assembly sequences requires an additional, more powerful, and flexible solution to \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Type** & **Name** & **Manufacturing Capability Features** & **Internal Dependency Features** & **Internal Dependency Requirements** \\ \hline
**Base Plate Systems** & Tool changing unit & Tooling & & 73 \(\times\) 73 mm\({}^{2}\) BPMS \\  & & & & Power supply \\  & & & & CAN port \\  & Needle Inspecting Unit & Inspecting & & 180 \(\times\) 290 mm\({}^{2}\) BPMS \\  & & & & Power supply \\  & & & & Ethernet port \\  & 3D Alignment Support & Supplying & & 365 \(\times\) 80 mm\({}^{2}\) BPMS \\  & & Positioning & & Power supply \\  & & & & Ethernet port \\  & Waffle Pack Support & Supplying & & 54 \(\times\) 110 mm\({}^{2}\) BPMS \\  & Conveyer & Conveying & & 73 \(\times\) 73 mm\({}^{2}\) BPMS \\  & & & & Power supply \\  & & & & Ethernet port \\  & Die Eject Unit & Feeding & & 500 \(\times\) 300 mm\({}^{2}\) BPMS \\  & & & & Power supply \\  & & & & CAN port \\ \hline
**Accessories** & Tool adapter & - & - & - \\  & Drip tray (300 mL) & - & Drip tray & 88 \(\times\) 120 mm\({}^{2}\) BPMS \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Base plate systems and accessories used for PlaTooMA. draw and modify objects on the screen. This can be achieved by a JavaScript 2D- or 3D-graphics library that is usable alongside Angular like fabric.js, PixiJS, or Konva. For Configurator, fabric.js was used, which is also installable through the npm. Figure 6 shows a screenshot of the implemented Configurator application. Two databases were established for the implementation of the method.