Smart Nodes are intelligent components of sensor networks that perform data acquisition and treatment, by the virtualization of sensor instances. Smart Factories are an application domain in which dozens of these cyber-physical components are used, flooding the network with messages. In this work, we present a methodology to reduce the number of calls a Smart Node makes to the network. We propose grouping individual communications within a Smart Node to reduce the number of calls is important to improve the efficiency of the process. The paper exposes and explains the Smart Node internal structure, formally describing the problem of minimizing the number of calls Smart Nodes make to Cloud Services, by means of a combinatorial Constraint Optimization Problem. Using two Constraint Satisfaction Solvers, we have addressed the problem using distinct approaches. Optimal and sub-optimal solutions for an actual problem instance have been found with both approaches. Furthermore, we present a comparison between both solvers in terms of computational efficiency and show the solution is feasible to apply in a real case scenario.