Communication of IT-Architecture

Abstract

This PhD thesis contains the results of various research activities that fall under the topic ‘communication of IT-architecture’. The term IT-architecture defines the various types of architecture that can be found in the domain of Information Technology (software architecture, enterprise architecture, etc). Our overall conclusion is that good communication of IT-architecture is a matter of “meaningful structuring”. This has been worked out in de following sub topics. A collection of 158 guidelines is presented to improve the readability of IT-architecture diagrams. These guidelines cover visual attributes like layout, hierarchy, colour, lines, graphics and text. Additional guidelines address the design of diagrams and give support for integrating diagrams in text. IEEE Std 1471 is proposes a conceptual model for documenting IT-architecture. Central concepts are ‘stakeholder concern’ and ‘views’. For four real life, pre-IEEE 1471, IT-architecture documents we investigated the pattern of relevancy to the stakeholder concerns. For each document a table was compiled that shows the relation between the parts of the document and the concerns of the stakeholders, as perceived by the authors. These tables show scattered patterns. For a stakeholder concern often only 25% - 50% of the document is relevant. The patterns show no evident way to convert the documents into IEEE 1471 views. We conclude that an structure of IEEE 1471 views needs to be incorporated in the setup of an IT-architecture description right from the start. To achieve this, we propose a method to define IEEE 1471 viewpoints. The method consists of four steps: compile stakeholder profiles, summarize architectural design, relate the summary to the concerns of the stakeholders, and define viewpoints. For each step support is offered in the form of Word templates or Visio diagrams. The IT-architects of one of the companies that took part in our research indicated that they did not like to define their own viewpoint, but rather work from available library viewpoints. To produce these for them, a round of stakeholder interviews was designed and an inquiry tool was compiled to solicit concerns (topics that are meaningful to the stakeholders). The tool is a questionnaire that covers a range of strategic IT-aspects. The tool was used to evaluate the existing architectural documentation practice. So many architecture frameworks have been proposed in the past 15 years. We wondered which lessons could be learned from them. Based on an overview of 23 architecture frameworks we present nine base dimensions that structure collections of architecture documents: Type of information, Scope, Detail level, Stakeholder, Transformation, Quality attribute, Meta level, Nature and Representation. Architectural information is most often structured in two dimensions: one dimension addresses the type of information, and a second one has a sequential order Finally, for easy communication a lightweight Enterprise Architecture Modeling method is presented, based on these key architectural concepts: Enterprise, Information flow, Enterprise function, Flow of products & service, Scenario step, Application, Computer, Network. EAM structures the information in five diagram types: Supply Chain Diagram, Enterprise Function Diagram, Scenario Overlay, Application Overlay and System Infrastructure Diagram.