Brands are business assets that can generate sustainable competitive advantage (Kozlenkova et al., 2014; Morgan, 2012). Specifically, brands may be seen as a potential source of value creation through the loyalty they inspire, their reputation, perceived quality, what they are associated with, and other aspects such as copyright (Aaker, 1991). They are also rather rare resources in that they require high levels of investment, and are difficult to replicate, since they help forge a unique relationship with their customers. Yet their mere creation is not enough to ensure that a brand becomes a valuable resource and a source of competitive advantage; they also need to be properly organized and managed by the firm (Kozlenkova et al., 2014).
• In general, firms do not tend to manage just one brand, but rather a group of them, known as a portfolio. The brands that make up a portfolio are organized such that they create a series of relations and links that endow them with consistency and a meaning that allows them to accomplish the firm’s strategic objectives. To achieve this, managers must design a structure, known as brand architecture, which clearly sets out each brand’s role and the relationships among them (Aaker and Joachimsthaler, 2000). Understandably, this architecture evolves over time so as to adapt to the challenges that emerge and to the firm’s new strategic proposals, which affects three of the portfolio’s key parameters: the number of brands marketed by the company, the internal relations between the brands and how they are positioned among consumers. In other words, as the brand architecture evolves, managers must take decisions aimed at expanding, consolidating or retracting their portfolio (Douglas and Craig, 1996).
