To find out whether there is a matrix below matrix #4 we would need to know the outcome of the "operation" of the product. Since matrix #4 describes all types of products there is no common engineering concept that grasps the outcome. In this sense the product model is fundamental to enterprise modelling.
To find out if there is a matrix above #1 we need to identify what operation brings about strategic enterprise management (SEM). We believe that processes which bring about SEM are beyond the realm of engineering and the enterprise - they belong to politics and education. Therefore the four matrices do cover the entire scope of enterprise integration.