The development of competency frameworks in healthcare professions is characterised by potentially inadequate descriptions of practice, variable developmental approaches, and inconsistent reporting and evaluating of outcomes. This may be in part due to limited existing guidance, which neglects broader contexts, lacks organising frameworks, and fails to provide guidance on selection of methods. To address such concerns, this paper first outlines a ‘systems thinking’ conceptual framework by which to conceptualise and describe clinical practice when developing competency frameworks. This is achieved through combining Ecological Systems Theory and complexity thinking to identify, and explore the contexts and components of clinical practice. The ‘systems thinking’ conceptual framework is then integrated into a six-step model for developing competency frameworks that synthesises and organises existing advice. The six steps include (1) identify practicalities (e.g. purpose, scope, detail, timeline), (2) identify influencing contexts and factors using ‘systems thinking’, (3) use aligned mixed-methods, (4) translate data into competency frameworks, (5) report processes and outcomes, and (6) plan to evaluate, update and maintain the competency framework. The model provides a logical organising structure of principles to guide assumptions and commitments when developing competency frameworks. Additionally, the model affords the flexibility required when exploring professional practice across varying contexts, and suggests employing mixed methodological approaches that are aligned with purpose and scope. The model acknowledges changing and complex contexts, considers existing guidance, and adds a unique and complementary means to conceptualise and improve the competency framework development process.