Prueba

Normalized Systems
Re-creating Information Technology based on Laws for Software Evolvability

Prof. dr. Herwig Mannaert Management Information Systems Department

Contents
• • • • • Settingthe Scene Supporting Theories Towards Evolvable Information Systems Towards Evolvable Enterprise Architectures Conclusions

1

The Business Challenge
• The Agile Organization
- Continuallyscans its ecosystem - Reacts quickly to opportunities and is innovative

• Has 2 Characteristics
- Complexity
• Multi-channel vs. single channel • Diversify offerings/Additional services

-Change/Evolvability/Flexibility
• “These things are changing so fast it’s invention in the hands of the owner.” (Hansen et al., 2007)

2

The ICT Challenge

The Law of Increasing Complexity MannyLehman
“As an evolving program is continually changed, its complexity, reflecting deteriorating structure, increases unless work is done to maintain or reduce it.”

Proceedings of the IEEE, vol.68, nr. 9, september 1980, pp. 1068.

2

Reference Frame
• Common ground between enterprises and IT is the structure or modularity • Combination of modularity and change means  EVOLVABLEMODULARITY • Enterprises need to be architected, engineered, and designed • Combination of design and change means  DESIGN FOR CHANGE

4

Contents
• Setting the Scene • Supporting Theories
-Evolvability of Artefacts - Systems Theoretic Stability - Statistical Mechanics Entropy

• Towards Evolvable Information Systems • Towards Evolvable Enterprise Architectures • Conclusions

3Saturn V

Static Modularity
6

The Theories – Part 1
• Stability in System Dynamics:
- In systems theory, the dynamic evolution of a system is studied based on a differential or differenceequation - A system is stable if and only if:
• a bounded input results in a bounded output • it has poles in the left plane or inside the unit circle:

- For a first order model, stability ...