A method for determining a wireless communication network realization in a plant where a process control system is provided includes receiving a user selection of wireless end point devices and locations of these in the plant, each being provided as at least one of a pair of endpoint devices that are to communicate with each other in relation to an automation function of the process control system, obtaining data communication requirements of the wireless endpoint devices, which are related to the automation functions and include at least one signal sent between a pair of endpoint devices and a time within which it has to reach its destination, and determining a number of wireless relay devices related to the locations of wireless endpoint devices in the plant for achieving a defined degree of radio coverage sufficient to satisfy the data communication requirements.