| S.No. |
Theoretical Modelling |
Identification |
| 1. |
Model structure follows from laws of nature. |
Model structure must be assumed. |
| 2. |
Modelling of input-output behavior as well as the internal behaviour. |
Only the input-output behaviour is identified. |
| 3. |
Model parameters are given as function of system properties. |
Model parameters are numbers only. In general no functional dependency to system properties known. |
| 4. |
Model is valid for the entire class of processes of a certain type & for different operating conditions. |
Model is valid for investigating system and within operating limits. |
| 5. |
Model coefficients are not known exactly. |
Model coefficients are more precise for the given system within operating limits. |
| 6. |
Models can be built for non-existing systems. |
Model can only be identified for any existing systems. |
| 7. |
The internal behaviour of the system must be known and must be describable mathematically. |
Identification methods are independent of the investigated systems and can be applied to many different systems. |
| 8. |
Typically lengthy processes which takes up much time. |
Fast process if identification methods exist already. |
| 9. |
Models may be complex and detailed. |
Model size can be adjusted according to the area of application. |
