This research aims to evaluate the potential success of grilled milkfish stalls in Sedati District, Sidoarjo Regency. The approach used in this research is a qualitative method by collecting data through observation and interviews. 6 informants were selected as research subjects to collect relevant data. The data collected includes initial capital, expenses and annual income. This data will be analyzed using the Net Benefit Cost Ratio (B/C Ratio), Revenue Cost Ratio (R/C Ratio), and Return On Investment (ROI) calculation tools. The results of calculations using this tool must exceed the number 1 (>1) so that the grilled milkfish stall in Sedati District, Sidoarjo Regency, is considered feasible to run. The results of the Revenue Cost Ratio (R/C Ratio) calculation will show how effective the income generated is in relation to the costs incurred.

This research applies a quantitative approach to determine the influence of customer income, price of goods, and quality on demand for PT heavy equipment spare parts. Indotruck Utama to consumers in East Java. The research method used is multiple linear regression analysis, with the help of SPSS analysis tools to test the hypothesis. In the results of this research, it was found that the results of the F Test simultaneously showed that the variables income (X1), price (X2), and quality (X3) together could influence the demand variable. Based on the results of the t test, it shows that the income variable (X1) partially has a significant effect on the demand variable, while the price variable (X2) and quality variable (X3) partially have no effect and are not significant on the demand variable (Y).