For the CAD software SOLIDWORKS a system extension is developed as an add-in. The focus of the project is on being able to adjust the CAD system more flexibly to the needs of the user. This makes working with the CAD system easier and increases efficiency. This project demonstrates the possibilities and advantages of an add-in. Only with the help of an add-in can the advantages of an established CAD system be fully exploited and at the same time the high costs for stand-alone software development be saved. Further information on Custom Toolbar and a download link can be found here: CUSTOM TOOLBAR (SOLIDWORKS) – FREE.