Modelling Guidelines
As models are used as a knowledge communication and collaboration platform both for humans and machines, their creation and documentation must follow thorough guidelines.
Models address a wide array of possible questions - as presented in the graph below - thus structuring them in a easy communicable, comparable and understandable way in of vital importance for their acceptance in user communities, inlcuding those dealing with ITSM.
How to model?
The Modelling Guidelines, where developed, at the University of Münster (Research Group Prof. Becker) in 1995, in analogy to the "Principles of Orderly Bookkeeping". They are a method-independent framework offering six principles of orderly modelling, which ensure a high model quality.

(1) Principle of Correctness | Requires models to be both syntactically and semantically corect. Consistency must exist both within the model and between different models. |
(2) Principle of Relevance | The model has to achieve the modelling goals (which requires explicit verbalization). Important aspects: (a) What is being modeled? (which part of reality), and (b) How it is being modeled? (which level of abstraction). A model should contain as much information as required and as little information as possible. |
(3) Principle of Economic Efficiency | Whatever effort is necessary to model something which is higher than the benefit/ROI of the model, should lead to a change or dropping of the modelling goal. |
(4) Principle of Clarity | Requires that models have a clear structure (e.g. all models are modeled in the same direction) and that they are intuitively accesible (comprehensible). Clarity requires also that models are readable (e.g. the names of objects are not to long, they are descriptive and clear in the context of the model used). |
(5) Principle of Comparability | Refers to comparability between - the current state and the desired/target state of the model
- the current state of the model and a reference model.
Comparability can only be determined relative to other models. |
(6) Principle of Methodic Structure | Demands for integration of different model views: - A common, view-overlapping metamodel is required.
- Thus when creating an isolated view, this has trade-offs for other views.
The principle requires the consistent use of modelling elements. |
Training material
Please use the training material below in order to get yourself acquainted with the specific application of the modelling guidelines, during your concrete work.
Training Material Modelling Guidelines