The eXtreme Design Approach

The eXtreme Design (XD) approach supports the design process of applications and application components.

Software Engineering
XD supplements existing software engineering methods such as Unified Modeling Language (UML) in the area of domain modelling.

Domain Modelling
Domain modelling is the task of discovering entities and objects of the application domain which represent real-world things and concepts.

Object-Oriented Concepts
XD combines object-oriented concepts with aspects of conceptual modelling on a higher-level of abstraction.

Meta Model
XD is based on the XD meta model which is adaptable to various application domains, and the XD algebra which offers a rich set of operations over the XD meta model.

Software Engineering Techniques
The eXtreme Design (XD) approach supplements existing software engineering techniques in three different areas:

• Prototyping
• Component modelling
• Information modelling

Software Evolution
XD supports software evolution and persistent data management by combining aspects of conceptual modelling and concepts of object-oriented software construction on a high level of abstraction through the XD meta model and its algebra.

Conceptual Modelling
From conceptual modelling, XD incorporates the idea of role modelling, i.e. the task of categorising and grouping objects and creating relationships between object groups.

Object-Oriented Modelling
From object-oriented modelling, XD supports the concepts of object identity, object aggregation, information hiding, extensibility and a special form of typing.