Layering, or the modular approach to information systems
In IT terms, layering is traditionally the process of setting up a software system by using hierarchical layers which communicate with each other. TCP/IP, for example, runs on this model. By extension, layering today involves segmenting an information system into modular, interdependent layers. Each layer is then minimally tied to the other layers. Virtualisation offers the necessary technology to implement a modular approach to information systems.
Why adopt a modular approach to information systems?
By their nature, information systems are very complex. In general, they include a physical layer, which delivers resources, a software layer, data, infrastructure services and uses.
The inherent problem with this type of infrastructure is that it creates a high level of independence between the various layers and their components. For example, a software application is closely linked to the operating system on which it is installed; this operating system, in turn, is further dependent on its physical server. For this reason, it is difficult to change one element without affecting all the others. The goal of layering is precisely to offer an intelligent way to "segment" infrastructure so as to allow for changes in the information system while ensuring easy installation.
focus on virtualisation technologies
Virtualisation technologies facilitate the modularisation of an information system. Generally speaking, virtualisation makes it possible to:
introduce infrastructure resources (laaS) by introducing a layer of abstraction,
virtualise existing physical servers (gaining independence from the physical layer),
virtualise software applications (no longer installed on the server, thus less dependent),
detach a user profile from a single workstation, thus taking a contextual rather than a content-based approach to the workstation.
In simpler terms, the modular approach to information systems helps to visualise an information system more precisely and with better granularity. At the same time, the user's understanding of the information system remains the same.