Non-profit organizations (NPOs) make an important contribution to society by providing products and services that are not typically offered by the private or public sectors. In today's world, most non-profits face significant challenges in remaining relevant and effective. Everything is changing, and unpredictability has become the norm. NPOs face important levels of ambiguity and complexity, as well as a variety of competing goals. Organizations in this sector are looking for new ways to improve competitiveness as a result of external variables, and leaders must rethink their organizational strategies. Organizational competencies assist organizations in dealing with complex situations and maintaining their competitive advantage. The purpose of this master's thesis is to create a holistic self-assessment tool for Complexity Leadership and provide a model to identify the level of development of organizational competencies under the framework of the leadership functions of the Complexity Leadership Theory (CLT). The CLT is a leadership model that helps to design resilient, dynamically adapting organizations and how to leverage informal dynamics within an organization. This theory provides a framework that describes three leadership functions (operational, enabling, and entrepreneurial) that must work in conjunction for an organization to succeed. The self-assessment tool considers the related questions to assess each of the identified organizational competencies under the proposed leadership functions of the CLT and its scale that allows organizations to understand the areas where it is required to improve.