SUMMARY
This study focuses on the use of Net Promoter Index developed by Frederik Reichheld and consulting firm Bain & Company, as a tool to know the perception of customers about the service they receive from their suppliers, this tool is an alternative to model SERVQUAL widely used for several years. This index consists of only two questions, which makes it an easier tool to use than other models. Currently this model is used by global companies like General Electric, Honeywell, American Express, Lenovo and others.The application of this tool is performed in a manufacturing company in the aerospace field in Mexico that has customers around the world. This study focuses on the relationship of the index to the Net Promoters Satisfaction and Customer Loyalty (Vestas method). The influence that may exist between some factors of the service such as Response Time Delivery, Price Competitiveness, Quality and Reliability with that index is also investigated.Note that in other studies published in journals such as Harvard Business Review has proven correlation between the growth in profitability with increased Promotion Index, as such the relevance of this study.In this research, a series of hypotheses are proposed to test the relationship between these factors with the Net Promoter Index. To try to test the hypothesis of structural equation modeling is used through the software SmartPLS.Based on the analysis and the results obtained in this study, conclusions and recommendations. Where it is concluded that there is a strong relationship of certain factors with Net Promoter Index, Satisfaction and Loyalty so based on improving strategy of these factors can contribute to an improvement in customer perception.