This developmental evaluation research project carried out within the Multisectoral Action Plan for the Reduction of Chronic Undernutrition in Mozambique begins to address the gap in understanding regarding the operationalization process and proposes strategic system thinking  to  advance  it.  A  main  contribution  of  this  dissertation  is  a  "proof  of  concept"  for the feasibility and exceptional insight to be gained by conducting such a study in a mode 2 fashion, using an emergent design responding to the evolving context and examining emergent research questions generated through direct engagement. Using a developmental evaluation approach with a group of key national stakeholders, the insights generated emerged from ongoing evaluation of multiple strategies to address operationalization challenges. Research methods included direct participation, document review, semi-structured and informal interviews, and the use of the Q methodology. Data were collected prospectively during 15 months in-country. Data analysis involved the use of several techniques and procedures based on a grounded theory approach. Multiple lenses, comprehensive and selective, were applied. The use of complexity concepts, system thinking and strategic capacity fostered additional insights to help dealing with complex systems. This dissertation also proposed a conceptualization of operationalization as a process of facilitating actions with the potential to induce tipping points and increase the performance level of a system. By using a case study design in which multiple embedded units of analysis were examined, the insights have implications for both research and practice. Of relevance to over fifty Scaling Up Nutrition countries, this dissertation illustrates how strategic, intentional, complexityaware actions by a small group of actors in a national system can produce meaningful outcomes, and how those can be assessed and accounted for. Based on this practical experience in Mozambique, a framework for strategic system thinking was developed; it can provide a valuable tool to help practitioners develop more effective strategies to influence various functions and elements of the nutrition policy process. The framework proposes strategic dimensions and a hierarchy of processes to be considered to address gaps and problems in complex systems. The framework also raises awareness on different types of catalysts for change and different order effects.