To create a competitive advantage through superior efficiency, an organization must

Reduce the number of inputs it requires to produce a given amount of outputs

Explanation:

Efficiency simply means producing more with less resources. In other words an organization or a business that is able to produce high quality products or output and spend less in producing these products is highly efficient and more likely to have superior efficiency to other companies making same product. A business that has competitive advantage by superior efficiency is able to sell at cheaper prices than other businesses in the market since it spends less and can afford to fix lower prices for it's products