Opportunity cost, also known as substitution cost, refers to the price paid or the potential benefit lost by choosing one scheme and giving up another in the process of economic decision-making. A resource in an enterprise often has multiple uses, that is, there are "opportunities" for multiple uses, but if it is used in one aspect, it cannot be used in another. Therefore, in decision analysis, it is necessary to take the potential benefits of the abandoned scheme as the opportunity cost of the selected scheme, so as to make a correct evaluation of the economic benefits of the selected scheme.

There are two main factors that affect the efficiency of enterprises:

On the one hand, it is the decision-making benefit. When an enterprise chooses scheme B and abandons scheme A, the possible income from implementing scheme A is the opportunity cost of choosing scheme B. Only when the expected income of the scheme selected by the enterprise is greater than the maximum opportunity cost of abandoning other schemes, the enterprise's decision is the most effective, which is called decision income. There are many such decision-making activities in enterprises, such as investment, procurement and pricing of internal production factors.

On the other hand, it is opportunistic income. Opportunity cost corresponds to opportunity income, that is, the expected income of the selected scheme. After an enterprise makes a correct decision, it does not mean that the opportunity income is the real income. During the implementation of the scheme, due to the objective and subjective reasons of the implementer, the actual income is lower than the opportunity income, which is the loss of opportunity income in the implementation process.