Keller, WolfgangDadam, PeterReichert, Manfred2019-10-112019-10-1120043-88579-380-6https://dl.gi.de/handle/20.500.12116/28731Today mergers of larger financial institutions are quite common place. You often find conglomerates that stem from a sequence of merger & acquisition activities. In each such case, IT management is confronted with more than one set of applications, often more than one IT service organization and the question is how to deal with such a situation. Typically management likes to reduce cost by migrating to just one application landscape and one IT service organization. This article describes a few observations and patterns how these challenges can be dealt with.enText/Conference Paper1617-5468