Relationship-oriented function modelling

Activities

• Activity 1: Clarifying and itemising the problem or Task
• Activity 2: Determining functions and their structures

Necessary tools

• Software support for easier restructuring of a large number of elements

Description

Relation-oriented functional modeling can promote system understanding by identifying strengths, weaknesses, useful and harmful components, and relationships in the system. In this way, development priorities can be determined and recognized.

Procedure

1. Formulate the goal of functional modeling: For what purpose should the system be abstracted?
2. Determine the appropriate level of abstraction, depending on the purpose of the abstraction: focus on essential aspects
3. Define the system boundary that separates the system under consideration from the environment
4. Determine the essential useful function of the system under consideration
5. Determine the main malicious function of the system under consideration
6. Are there other functions for which the (essential) useful function is required?
7. Are there functions that are required for the (essential) useful function?
8. Are there other malicious functions caused by the (essential) malicious function?
9. Are there functions that cause the (essential) malicious function?
10. Are there any features introduced to avoid the (essential) malicious feature?

Complete the functional model using these questions

1. The questions will be asked again for all newly added functions
2. Stop building the functional model when all important useful and harmful functions of the system under consideration have been mapped (3 or 4 iterations are usual).
3. Generate problem formulations to reinforce useful functions and to avoid/mitigate the harmful functions

Sources

• Kumke 2018
• Lindemann 2009, p. 301, 302