Branding dates back to centuries ago when traders were trying to distinguish their products from others in order to promise a higher quality to their consumers. Today, brands are considered as intangible resources that can have a significant contribution to the firm performance. Based on the Resource-Based Theory (RBT), valuable, rare, inimitable, and non-substitutable brands are strategic resources that create superior value and play a key role in achieving a sustainable competitive advantage over rivals. In the process of developing and maintaining strong brands, brand managers constantly need to make multiple decisions. Whether to add, delete or retail brands are among the routine decisions that brand managers face in managing their brand portfolios. Brand managers need to regularly assess their brand portfolios in order to make sure they are not selling redundant brands. Through brand portfolio assessment, brand managers can recognize weak brands and delete the unprofitable brands from the portfolio in order to free up resources and reinvest them in their stronger and more successful brands to gain competitive advantage in the market. This admonition is in line with the RBT of competitive advantage. This dissertation builds upon and extends previous literature on RBT in the context of brand …