1. Introduction
2. Four System Improvement Situations
2.1. Basic System Improvement Situation
2.2. Basic System Improvement Situation and Combinatorial Problems
2.3. Additional System Improvement Situations

3. Approaches to System Evaluation and Improvement
3.1. Spaces of System Quality and Improvement
3.2. Towards Reoptimization

4. Improvement by System Components
4.1. Basic Framework
4.2. Graph Vertex Recoloring Problem

5. Modification of System Structure
5.1. Modification of Tree-like Structures
5.2. Augmentation Problem
5.3. Transformation of Morphological Structure
5.4. Transformation of Layered Structure

6. Examples for Network Improvement/Extension
6.1. Network Hierarchy
6.2. Requirements/Criteria
6.3. Network Design/Development: Basic Problems
6.4. Network Improvement
6.5. Network Extension

7. Conclusion