Applying Design Principles in Practice

It is widely recognized that the systematic application of relevant design principles plays a key role in taming the complexity involved in real-world software development. In our experience as consultant architects and trainers on software architecture and design in a corporate setting, we find that software engineers have a theoretical understanding of design principles but sorely lack knowledge about how to properly apply them to in real-world situations to achieve high-quality design. This half-day tutorial is geared towards bridging this gap. It first introduces fundamental design principles (viz. abstraction, encapsulation, modularization, and hierarchy) and describes how these can be applied using a set of corresponding enabling techniques. Next, it discusses how design smells can be viewed as violations of these enabling techniques, and explains how these design smells can be refactored via the application of relevant design principles. Finally, it highlights useful tools, processes, and practical techniques that support the application of design principles in real-world software projects.