This paper proposes the concept of Demand Flexibility for the assessment of customer demand profiles. First a demand profile is modeled resorting to stochastic simulation techniques, including different appliances such as lighting, refrigeration, entertainment devices, among others. Second, different demand management strategies are applied in order to identify the flexibility of the modeled customer profile. This concept allows to analyze of Demand Response Models (DRM) applicable to Micro-grid with diversity of features and simulation tools.