According to Session 2006, all previous methodologies to understand EA failure share certain characteristic which is complexity. He argued that although the existing frameworks for developing EA all have their particular strengths and weakness, they do not fully address the challenge of complexity. Most organisations perceive EA to be a complex tool, due to this there is a great risk that the deliverables of EA are not met (Poutanen, 2012). In order to manage and mitigate complexity it is essential to fist get an in-depth understanding of what complexity is (Session, 2006).According to Janssen and Kuk (2006), a complex systems is a system which is made up of large number of parts which interact in a non straightforward way. It is considered by Rogers and Salingaros, 2010 as an attribute of a system which makes the system difficult to use, understand and manage Complexity doesnt occur by accident rather it is an innate property of large systems (www.agile-architectingsystems.com). Architecture is considered complex due to its numerous components and their relationship (Holt an Perry, 2010). In the context of EA, complexity refers to an organisation of large number of IT systems whose relationship and interaction are difficult to understand. EA is characterized by its high complexity due to its wide range of various domains and scope (Rohloff, 2005). Complexity has its origin from the idea of structural fit, where organisations are forced to adapt to the ever changing environment to remain competitive (Gravesen, 2012). As Enterprises grow in size they tend to reach a point where the factors that come into play in structuring and defining its business become to numerous thus developing into complex situations which are difficult to manage (Iyer and Gottileb, 2004). While Gravesen, 2012 argues that complexity in enterprises results from continuous growth and the need for periodical changes, Session, 2009 argues that complexity goes up as the functionality of the systems increases resulting in increased interactions between all the components and systems in present in the Enterprise. However it can be argued that the complexity of a system is highly impacted by it functionality, size and its dynamic nature due to the changing environment. According to Buchanan (2011) an enterprise is usually made up of about 15 to 25 top-level business processes which constitute of a number of interlinked and mutually dependent process (Strnadl, 2006) therefore to address complexity which may arise an organized arrangement of the business processes is required (Tian et al., 2006). The complexity of a system is always as a result of the relationships and interaction among many heterogeneous sub-systems which manifest itself at any point in the system (Holt and Perry, 2008; Gammelgard et al., 2007).
however, i would need some answers to the following questions
1) what the root causes of enterprise Architecture complexities?
2) what tools and Techniques have been used to address this complexities?