The PPAN monitoring and evaluation system uses the following schemes except:

The monitoring and evaluation system of the PPAN (Philippine Plan of Action for Nutrition) primarily focuses on schemes that provide practical and actionable data regarding nutritional status and program effectiveness. Among the options, policy formulation is not a scheme utilized for direct monitoring and evaluation within this context.

Nutrition surveys and OPT (Operation Timbang) provide essential data regarding undernutrition in communities, allowing for precise tracking of nutritional health. Nutrition surveillance continuously monitors the nutritional status over time, making it central to understanding trends and impacts of interventions. The annual evaluation through the MELPPI system is designed specifically to assess the implementation of local plans and their effectiveness regarding nutrition.

In contrast, while policy formulation is critical for setting guidelines and priorities, it does not fit within operational schemes specifically aimed at monitoring current nutritional conditions or the effectiveness of existing programs, which is the focus of the other options. Thus, understanding the practical application of each term helps clarify why policy formulation stands out as the exception in this context.