Over the past few years wireless sensor networks applications have evolved from a stage where these networks were designed in a technology-dependent manner to a stage where some conceptual understanding issues now exist. As wireless sensor networks are deployed, energy consumption emerges as a core requirement. Recent advances in energy harvesting technology for wireless devices have increased the lifetime and performance of wireless sensor node. It is useful to get a tradeoff between the duration of energy harvesting and network reliability. Previous investigations are mostly focused on duty cycle optimizing. An interrelation of energy harvesting schedule and network reliability has not been considered. To fill this gap we formulate optimizing problems for operation strategy of Energy Harvesting Wireless Sensor Networks. A problem solving approach is considered as well.