– Those who want to learn about AOM ?nd in this special issue a concise collection of descriptions of solid and mature AOM approaches. They only have to take the time to understand one case study in order to appreciate the sample models shown in all papers. – Those who want to apply AOM for a particular purpose and are looking for the most appropriate AOM technique can use the papers presented in this specialissue to identify the mostpromisingapproach(es).By identifying similarities between their problem and the case study they should be able to determine candidate AOM approaches easily. – Those working on their own AOM approach can readily identify approaches that were able to handle concerns that their own approach is not able to handle elegantly. This stimulates cross-fertilization between approaches and collaborative research. – Thoseengineering researchersthat areworkingon enhancing softwaredev- opment processes can use the example models presented in this special issue to understand the potential bene?ts of using AOM techniques at di?erent phases of the software development life-cycle.

Guest editor: Jörg Kienzle