A core competency has three defining factors: $1)$ It provides potential access to a wide variety of markets, $2)$ Competitors should find it difficult to imitate, and $3)$a$)$ The maturity and decline phases of all products and services will be avoidedb$)$ It will eliminate external risk c$)$ It makes significant contribution to the perceived customer benefitd$)$ Supply chain friction costs will be reducede$)$ It will eliminate internal risk