Why does ERP's performance decrease when the functionality increases, And why it can't be otherwise
If we look at the classic modular ERP system (a CRM system integrated with a WMS system, with a "main" ERP, etc), it is not difficult to show that its maximal effectiveness throughout the enterprise is limited by intermodule synchronization (module-to-module communication).
More precisely, the maximal effectiveness of an enterprise's "global" modular ERP system (defined as a large number of types of data objects which are "globally" accessible) will be limited by the intersections of all types of data objects passed through each individual synchro-joint.
This supports the theoretical and counter-intuitive (but widely known through experience) fact that the actual effectiveness (as well as the actual performance) of modular ERP systems, when the number of integrated synchro-joints is increased, rapidly decreases.
In reality, additional "modules" are purchased and integrated in order to boost effectiveness, though.
It would however be strange if it were any different.
Empirical data supports the conclusion that the greater functionality ERP formally has, the less functional it is in reality.
Conversely, the maximal effectiveness of the system is achieved when intermodule joints are completely eliminated.
That is to say that the maximal effectiveness of the system is achieved when the system consists of one module only.
Thus, using a contrario reasoning, we come to the imperative of IEM System's exceptional inclusiveness and singularity.