Visual Software Modeling-UML (version 2.0) There are many ways to represent a system, everything from simple sketches consisting of boxes and arrows, to sophisticated representational 3-D models. For very complex systems, a number of detailed schematic approaches have been developed. Blueprints have been used for many years to represent complex building projects. Electrical engineering schematics are used to represent the massive complexity involved in silicon chip manufacture. Plumbing, lighting, decorating, and landscaping all use detailed diagrams to represent an abstract view of the finished product.