The objective of this study was to study the data to use in making decisions for the executive of Fertilizer plant of Rajamangala University of Technology Lanna about the cost of some production. Using primary data store for storing and collecting accounting data and secondary data by the data collected, stored and analyzed
The results of the study found that the company decided to own produce or buy when production can save cost more than buying the company should to own produce if the cost of buy is lower than own produce the company should continue to buy instead of own production to save costs. When selecting products for limited resources, consider the gross profit attributed to capacity and should refuse to produce and sell certain products at a profit is not worth the labor. In the co-products if the manufacturer has added more profitable than selling the company should be continue produce, but production does not cause an increase in profit the company should be sell at the point of sale. When the company received a special order if the special orders, there was an increase in profit does not accept special order. Finally the decision to add or cancel product if the cancellation product line contributes to the overall profit of the company decreased the company should not be canceled product line if it is found that increasing the product line already has excess profits rather than a fixed cost that is directly the company is also supposed to be used that way.