The aim of this study is to analyze the results of a research carried out in Brazilian manufacturing companies that have typical initiatives of Industry 4.0, in order to identify the main challenges and opportunities of building a flexible industry and to provide elements that enable manufacturers to guide this construction with a little more security. Through the literature review, 28 challenges and 23 opportunities were identified and submitted by a questionnaire to 39 leaders of national and multinational manufacturing companies in Brazil, identifying which challenges and opportunities were the most and the least important. This study brings two theoretical contributions: it enriches the literature on challenges and opportunities of flexibility and draws attention to issues on the implementation of a flexible industry that needs studies. The management contributions are: (1) show the relative importance of 28 challenges and 23 opportunities and (2) detail the content of 24 questions (the 6 most and the 6 least relevant challenges and opportunities) in order to give certain security to the manufacturers to guide the building of the flexible industry and direct implementation actions. The limitations of this study are the reduced number of companies and segments of economy observed (Auto Parts, Metal-mechanics and Metallurgy) for an empirical study and the opinions of leaders in a moment, which may change, not allowing generalizations.