Zielgröße

Zielgröße is a German term used in engineering, science and management to denote a target quantity or objective that a system should achieve. It is commonly used in control theory and process optimization to describe the value the process variable is aimed at reaching.

In the context of control engineering, the Zielgröße corresponds to the desired value of the controlled variable and is often referred to as the Sollwert or setpoint. A controller compares the current value of the variable (die Istgröße) with the Zielgröße and computes a control action (Stellgröße) to reduce the deviation. Disturbances (Störgrößen) can affect the process, requiring the controller to adjust the Stellgröße to keep the system close to the Zielgröße. In many texts Zielgröße and Sollwert are used synonymously, though some authors distinguish between the goal (Zielgröße) and the numerical reference value (Sollwert).

Beyond regulation, the term is also used in optimization, experimentation and performance management to denote the metric or outcome being pursued or evaluated. For example, a chemical reactor might have a Zielgröße of a specific conversion rate or yield; a temperature control task might aim for 70 degrees Celsius; in data analysis, the Zielgröße can be the dependent variable or response to be optimized.

Etymologically, Zielgröße derives from Ziel (goal, target) and Größe (size, quantity). The concept emphasizes the intended result of a system’s operation, against which actual performance is measured by error metrics such as absolute or relative deviation.