It has been said that the rules for success are written outside the organization but competitive advantage must be found within the organization.

After reading the lessons Chapter and watching the video lecture please answer the following question:
It has been said that the rules for success are written outside the organization but competitive advantage must be found within the organization. Explain this statement. Support your thoughts.
***I am on chapter 4 from a textbook ” STRATEGIC MANAGEMENT OF HEALTH CARE ORGANIZATION” by Peter Ginter, Jack Duncan and Linda Swayne. if you can you it as 1 on the references , if possible***