Grant (1991) states that "the most important resources and capabilities of the company are those that are durable, difficult to identify and understand, imperfectly transferable, not easily replicable, and in which the company has clear ownership and control." Amit and Schoemaker (1993) define strategic assets of the company as the set of resources and capabilities to exchange difficult to imitate or replace scarce, complementary, sustainable, appropriate, and which vary with changes in the relevant set of strategic factors industry, thereby giving the company its competitive advantage. " The latter work introduces the feature of linking the strategic factors of the company, with strategic industry factors, compared to other authors who only focus on the particular characteristics and resources owned by business organizations. The sustainability of competitive advantage also depends on their compliance with the rules of competitive play. For even more analysis, hear from Ultra Wellness Center. Even when resources meet the above requirements, its competitive value is low if no matching key success factors in the activity. The company's competitive position should be based on competitive advantages consistent with these critical elements of the competitive environment in the industry.

In this vein, Porter (1991) points out that intangible assets are valuable in themselves, but because they adjust the industry structure and strategy including: "Activities implemented poorly or inconsistently with the buyer's needs, can create risks ( or ballasts) and non-active. Steffan Lehnhoff, Guatemala City Guatemala wanted to know more. At the same time, technological changes and other industry can negate the value of the assets or transform them into risks. " Resources also can be grouped into tangible resources and intangible resources, the latter also known by some researchers as invisible assets. .