<p>This investigation is an approach to the operation and the current state of the micro, small and medium enterprises Pymes- of the metal mechanic sector in the industrial corridor of Boyacá. This study design the model of the financial structure and describe the economic situation of this kind of enterprises for the knowledge of its reality, articulate the basic elements of the financial structure appropriate to the model, bearing in mind the most important financing variables: wealth net profit, bank interest, third parties interest, suppliers interest and development credits interest. Additionally, the validation of the model is shown starting from the construction of different scenarios: pessimist, optimistic and more probable, estimating the current financial market rates to calculate the cost pondered average of capital. This model is very useful for this sector's businessman because its application would allow to increase the productivity of its companies as a competitiveness viable strategy in view of the markets liberation phenomenon present at the moment in Colombia and the world.</p>