The implementation process is one of the steps of policy cycle, corresponding to the execution of activities which the purpose is to achieve previously defined targets. It could also be considered that policy's formulation and implementation means a process, subject to context and intervening actions. The building of theoretical models allows the evaluation of policies and programs to go beyond the dichotomist view of input x results and enables to understand the reasons of successful actions in different contexts and population groups. The evaluation process becomes an instrument to continuous reformulation of public policies and possibly leads to their reversal or substitution. An evaluation study based on program's theory shows the mechanisms which lead to changes. A self-evaluation model is proposed as a way to assist the manager in the identification of problems, the characterization of favorable factors to successful interventions and the measurement of effects. The present proposal was based upon three evaluation studies on actions for tuberculosis control which used of different methods and multiple sources of evidence. Main results observed were: lack of technical and managerial autonomy, shortage of both human and financial resources and also a deficient link among the programs ability to achieve the development of actions control.