Core competencies are highly valued by managers since, among other things, they underpin competitive advantage. One stream of research in this area has focused on practical processes relating to the identification of single and multiple core competencies. Yet, identification is insufficient for sustaining core competence‐derived competitive advantage, since a core competence needs continuous development. Organizations typically possess multiple core competencies, which most likely have different origins and requirements of the developments. They typically underpin different markets and products; face different degree of dynamic conditions, and so on. Thus, it is our contention that core competencies accordingly ought to be managed separately.In this paper, we advance existing core competence research by identifying similarities and differences in influences on three core competencies. Three concepts were used to assess the similarities and differences in one case company; the latter to avoid empirical bias. The three concepts are competencies, capabilities, and resources: all commonly applied to core competence issues, such as identification.All three core competencies were heavy influenced by specific competence attributes: technological developments and customers adaptation, which are fundamental to the case‐company's success. This finding brings in a context‐dependency aspect to core competence management.The core competencies were also found to have differences in the less context‐dependent influences. The more complex the core competence, the more it is influenced by transfer and adaptation competencies, as well as by organizational capabilities. Resource influence clearly separates a service‐producing core competence, which is mainly influenced by organizational capabilities, from two goods‐producing core competencies which are not so influenced. The more complex of the goods‐producing core competencies is more strongly influenced by both tangible and intangible resources. Copyright © 2007 John Wiley & Sons, Ltd.