This research work revisited the age-long debate on the source of competitive advantage and its sustainability by a business organisation which has pitched the resource-based theory against industry organisation theory over the years. Qualitative design using idiographic philosophy and secondary data was adopted. The question: can either resource-based theory or industry organisation theory alone help business organisations to achieve competitive advantage was raised and addressed. The thrusts of resource-based and industry organisation theories in relation to source of competitive advantage were highlighted and discussed. The findings were that neither the resource-based theory nor industry organisation alone can deliver competitive advantage to business organisations because business organisations need to exchange the value created using their resources with customers in the marketplace and vice versa. Thus, equation of competitive advantage was modeled. It was concluded that the two theories be integrated based on their strengths to better achieve competitive advantage for business organisations than operate separately. Therefore, it was logical to recommend the integration of the strengths of both theories into RBIO hybrid theory for the holistic benefit of business organisations. The RBIO hybrid theory recognises that the merits of both theories will give business organisation strategic edge which spells competitive advantage through rigorous implementation. Empirical verification of the RBIO hybrid framework is also recommended to academics, practitioners and professionals in the field of strategic management.