Enterprise software should be built with the main priority to solve business problems, leading to business-driven applications and technology rather than to technology-driven solutions. The business use cases are what ultimately will generate revenue for the company.

If possible, enterprise applications should be developed in one build project per artifact, kept under version control. Splitting up a project into several, independent build modules that are in the end boiled down to a single artifact, doesn't add much value. For the coarse project structure it's advisable to structure the software modules vertically, not horizontally. This means to structure by business rather than technical concerns. Looking at the project structure should immediately tell developers what the project's domain and responsibilities are about.

An individual application module can, in the simplest way, be designed as a single, flat Java package. This is advisable if the number of classes per module is small. For more complex modules it makes sense to add another hierarchical layer using patterns such as Entity Control Boundary.

Software engineers should be reminded not to over-enforce software architecture. Well-thought-out design and bureaucratic organization certainly support developers a lot in crafting high quality software. Still, there is always a happy medium between reasonable design and over-engineering.

After seeing the course structure of enterprise projects and how to design modules, let's dive down one level to how to realize project modules. The following chapter will show you what it takes to implement enterprise applications with Java EE.