Dewey Decimal Classification (DDC) is the most widely used classification system internationally. It was developed by Melvil Dewey in 1873 based on the Decimal Classification conceived by Gottfried Wilhelm Leibniz in the 17ᵗʰ century. At the dawn of the 21ᵗʰ century, DDC attracted great interest amongst academic libraries in Europe, and was translated into German and several other European languages. The contemporary Dewey Decimal System with over 48.000 classes and six tables allows a huge flexibility and fineness in building new numbers such as 700.90440747471. However, this process is complex and is based on several intricate rules and instructions. The lack of captions in such built numbers makes it difficult to understand and re-use by the non-Dewey catalogers. Thus, in 2003 under the project VZG-colibri, a sub-project coli-ana was initiated to develop a tool that would automatically decompose and analyze any given DDC notation to its tiniest component, enrich them with their caption, and provide the semantic relationship between each element in JSKOS (a JSON-LD format based on SKOS). The results of coli-ana improve information retrieval, facilitate re-use, and aid further study to enhance knowledge organization systems in general. coli-ana delivers DDC captions only in German, but it is planned to integrate the English version of DDC as well. The results of the tool are incorporated in the mapping tool Cocoda as well to assist mappings to and from DDC built numbers. This talk will give a brief background of the project coli-ana, elucidate with examples the decomposition of notations with their adherent rules and instructions, present the coli-ana web service as well as demonstrate its use cases in the project coli-conc and in the K10plus union catalogue.