The data stream processing strategy based on measurement metadata, is an enhanced approach that relies on a measurement and evaluation conceptual framework. The strategy uses measures (data sets) and their linked metadata to incorporate detective and predictive behavior as well as to trigger alarms in a proactive way. This work discusses the process formalization for its data stream processing components, and their interactions. The process specification is based on the SPEM language, and the main specified activities ranges from data source configuration of heterogeneous data sources, to statistical analysis and classifiers for decision making. As result, the proposed strategy becomes more consistent, repeatable and communicable from the process modeling viewpoint. Also, to illustrate the approach, excerpts of a developed outpatient monitoring system are used.Sociedad Argentina de Informática e Investigación Operativa