System complexity
System complexity enables the classification of systems of all kinds. On this basis, you derive your further procedure for reviewing, communicating, or control. The usage goes across all meaning design levels, i.e., idea development, communication management, and business design.
The system complexity results out of two dimensions: the variability/ dynamic and the variety/ diversity. (The model is based on a model of Ulrich/ Probst; Anleitung zum ganzheitlichen Handeln)
- Variability/ Dynamic
The variability comes from whether the system changes in the defined time frame (dynamic) or not (stable). The considered time frame can be short or long term. Stable systems allow a detailed and long-term investigation because the system is not changing. Dynamic systems require a needs-oriented and fast approach.
- Variety/ Diversity
Variety comes from the number of elements that define a system. Diversity comes from the heterogeneity of the features. The number of parts can be manageable or not. A simple system consists of a few homogeneous elements; the most straightforward case might be one. The system becomes complicated with heterogeneous components, in the most complicated case a lot and always different.
A grid of four fields is created based on these two dimensions: simple, dynamic, complicated, and complex.
- Simple
Simple systems with few elements are easy to describe and need little attention after they function – e.g., simple commodities (e.g., knife, bottle) and a house's construction plan. You can use images and texts to describe the elements.
- Dynamic
Dynamic systems with few elements are changing in the course of a particular time. The changes are happening fast or slow with a regular or irregular rhythm. The few parts can be well described but have to be held current and expanded over time – e.g. heating systems, beverage storage, and gas tank. Besides the documentation of the elements, additional aspects have to be explained, e.g., former changes and/or mechanisms of change (e.g., the range of a thermostat).
- Complicated
Complicated systems with many elements are challenging to understand but can be well described according to time. To ensure the up-to-dateness, the documentation must be reviewed regularly, whether something has changed – examples are city map, train route network, engine plan. The documentation consists of many figures and texts of the elements due to complicatedness.
- Complex
Complex systems cannot be entirely documented because the variety and diversity are huge and always changing before the description can be finished. To remain usable, a different level of explanation is required. Therefore, for example, weather systems, social systems, traffic jam planning use, in addition to a rough description of the elements, model simulations with causal relationships, probability statements, and pattern descriptions.
You can describe any system in a way that it ends up appearing too complex or too simple. You have to decide on what level of detail you are working. Small-scale descriptions show many starting points for small changes but lose the overview and do not show basic action options. Rough descriptions tend to provide significant changes, but they do not show the small adjusting levers that could impact a lot.