Starting with the transformation to client-server systems from mainframes and later with the advent of e-Business and J2EE, large enterprises moved predominantly into a highly network-based distributed network computing environment with firewalls and demilitarized zones. Currently, most of the applications have a web front-end and, looking at the deployment architecture of these applications, it is very common to find three distinct layers in the network landscape; namely a web presentation layer, an business logic or application layer, and a back-end data store layer. It is a common practice for applications to be deployed and hosted in a shared and common infrastructure environment.

So it becomes highly critical to document the mapping between logical applications and the technology components (e.g., server) that supports the application both in the development and production environments. The purpose of this diagram is to show the "as deployed" logical view of logical application components in a distributed network computing environment. The diagram is useful for the following reasons:

• Enable understanding of which application is deployed where in the distributed network computing environment
• Establishing authorization, security, and access to these technology components
• Understand the Technology Architecture that support the applications during problem resolution and troubleshooting
• Isolate performance problems encountered by applications, determine whether it is application code-related or technology platform-related, and perform necessary upgrade to specific physical technology components
• Identify areas of optimization as and when newer technologies are available which will eventually reduce cost
• Enable application/technology auditing and prove compliance with enterprise technology standards
• Serve as an important tool to introduce changes to the Technology Architecture, thereby supporting effective change management
• Establish traceability and changing application end-point address while moving application either from a shared environment to a dedicated environment or vice versa

The scope of the diagram can be appropriately defined to cover a specific application, business function, or the entire enterprise. If chosen to be developed at the enterprise level, then the network computing landscape can be depicted in an application agnostic way as well.