This paper shows how a business model relates to the fixed cost, the capital budgeting
decisions, and the cost of capital. The model is an extension of the contingent claim
methodology to corporate finance by constructing the primitive firm of a business sector.
The model results show that the firm’s capital budgeting decisions can be affected by the
fixed costs of the firm. In providing a valuation model of the firm, we can analyze the
optimal capital budgeting decisions by seeking the optimal control variables in
maximizing the firm value. As a result, the model can be used in a broad range of
corporate finance decisions.

