“A complex system that works is invariably found to have evolved from a simple system that worked. The inverse proposition also appears to be true: A complex system designed from scratch never works and cannot be made to work. You have to start over, beginning with a working simple system.” Galls Law
The first step in creating a lean enterprise is to first assess all your systems. Find out where these systems overlap and then see if these can be integrated. You would be surprised how much functionality and data is duplicated across your enterprise environment. In some cases the duplication is needed, but in the vast majority of cases the processes can be streamlined through either automated processes or removing the duplicate areas altogether.