1.1 Definitions

The software fortress is the basis for the software fortress model, so I'll start by defining that:

Definition: Software Fortress

A software fortress is a conglomerate of software systems serving a common purpose and typically owned by a cohesive group of individuals. These software systems work together in a tight trust relationship to provide consistent and meaningful functionality to a hostile outside world.

As you can see, the definition of a software fortress includes both technical and organizational aspects. From the technical perspective the software fortress is a collection of systems. This collection can consist of many different types of software systems, including but not limited to processes, system services, component-packaged business logic, and databases.

From the organizational perspective, the software fortress encompasses people who work together, have a reasonably clear sense of what each other is doing, have a fair amount of trust in each other's systems, and are probably separated by no more than two levels of management (i.e., their managers all report to the same person). In my experience these people are often part of the same department. In some companies, the software fortress organization may consist of informal relationships. The personnel probably include developers, architects , managers, quality assurance specialists, deployment specialists, and often technical writers.

This book will look at the technical aspects of software fortresses. However, the political boundaries within the company should somewhat reflect the organizational boundaries of the software fortresses , at least at a given point in time. If you find yourself spending a great deal of time on unproductive squabbles, you probably have a misalignment between the organizational and technical boundaries.

Given this definition of a software fortress, we can now consider a software fortress architecture:

Definition: Software Fortress Architecture

A software fortress architecture is an enterprise architecture consisting of a series of self-contained, mutually suspicious, marginally cooperating software fortresses interacting through carefully crafted and meticulously managed treaty relationships.

Finally, we have the definition of the software fortress model:

Definition: Software Fortress Model

The software fortress model is a methodology consisting of specific algorithms, categories of technologies, and documentation techniques that together can be used to model and build enterprise systems as software fortress architectures.

As we will see, the software fortress model includes techniques for describing how systems interoperate , maintain proper trust relationships, and pass information back and forth. The model also gives strong clues about which technologies are appropriate to use for connecting software fortresses, which technologies are appropriate to use within the software fortress, and which technologies map well to specific fortress types.