1.1 The Definition of IT Infrastructure

During the first decades of IT development, most infrastructures were relatively simple. While applications advanced in functionality and complexity, hardware basically only got faster. In recent years, IT infrastructures started to become more complicated as a result of the rapid development and deployment of new types of applications, such as e-commerce, Enterprise Resource Planning (ERP), data warehousing, big data, the Internet of Things, and cloud computing. These applications required new and more sophisticated infrastructure services, secure, highly scalable, and available 24/7.

Most current infrastructure landscapes are the result of a history of application implementation projects that introduced their own specialized hardware and infrastructure components. Mergers and acquisitions made things even worse, leaving many organizations with multiple sets of the same infrastructure services that are hard to interconnect, let alone integrate and consolidate.

Organizations benefit from infrastructure architecture when they want to be more flexible and agile, because a solid, scalable, and modular infrastructure provides a firm foundation for agile adaptations. The market demands a degree of flexibility that can no longer be supported by infrastructures that are inconsistent and hard to expand. We need infrastructures that are constructed with standardized, modular components. And to make infrastructures consistent and in line with business needs, architecture is crucial.

Architecture is the philosophy that underlies a system and defines the purpose, intent, and structure of the system. Various kinds of architecture can be defined, including business architecture, enterprise architecture, data architecture, application architecture, and infrastructure architecture. Each of these disciplines has certain unique characteristics, but at their most basic level, they all aim at mapping IT solutions to business value. Architecture is needed to control the infrastructure when it is designed, in use, and when it is changed.