In a fast movement environment where organizations are struggling to survive and succeed in the market, the focus is increasingly placed on resources that can provide a sustainable competitive advantage. Wright, McMahan and McWilliams (1994), like other researchers have realized that human resources can generate this advantage since they are rare, difficult to substitute and imperfectly imitable. The more human resources are exploited and the more they get enriched and provide added value to the organization through creativity and innovation.We note that the prerequisite for the added value creation is individual motivation and competence at work. Thus, it is assumed that the development of human resources management enables to meet the competitiveness challenge. Human resources managers have to enhance staff motivation and to ensure continuous knowledge improvement. ISSN 2157-6068 2016 www.macrothink.org/bms Business Management and Strategy 65In this research, we try to explain the link between the human resource management practices and performance through the contingency approach. To do this, we opt for the subgroup analysis as a methodological framework. Our results lead to recognize that the interaction effect between certain human resource management practices and innovation level can provide an explanation as to changes in the level of performance of the Tunisian industrial firms.