Principles as a Complement to Models in Defining the Target Enterprise Architecture

The main reason to adopt an Enterprise Architecture framework (EAF) is to manage change; moving from where an organization is today, to where it needs to be in the future. The challenge in this is to understand what to change, why to change it, to what it should be changed and how to manage that change or migration. Existing literature in the EA area of research often describes how successful understanding and description of both current and target architectures can be derived from visual models, and the migration work is often described as a project or program. As a complement to defining the target architecture as a model, architectural design principles can be used and the EA work can also be seen as an ongoing change process. However, existing frameworks give very little support for working with principles as a complement to models. The purpose of this paper is to create a better view of "in what situations should the understanding of the future architecture of the enterprise be derived by a model and in what situations should it be derived from principles or a combination of both?" To investigate this two real-life cases are analysed. Our conclusion is that factors like time, dynamic external environment, and complexity of business tend to draw organizations towards increased uncertainty of the future. Models become less meaningful as they will most likely lose their validity over time and they simply cannot accurately represent the future. In these situations an architectural principles can support the architecture migration.