This paper proposed a RF-based mapping-based indoor localization technique to locate their packages and items. The Received Signal Strength Indicator (RSSI) is commonly used in trilateration to allocate the packages or items location. However, several problems need to overcome to increase the accuracy of the RSSI signal propagation for the localization. The problems include the complexity of the indoor environment will affect the radio waves experienced multipath effect such as the signal may be reflected, refracted, absorbed or blocked by other matter. The paper is designed to study the propagation of radio waves in indoor conditions, identify the type of antenna used and determine the accuracy of the localization model. The RSSI is recorded for every 1m until reached the maximum read range of 20m to study the behaviour of radio waves propagation and the relationships between RSSI and distance. The RSSI mapping experiment was carried out to determine the type of antenna used to carry out the experiment. The localization is performed with mapping-based technique to predict the random coordinates in the testbed. The predicted coordinates and actual coordinates were compared to determine the accuracy of the localization model. The error between the actual coordinates and predicted coordinates can achieve an average of 0.95 meter. The RF mapping-based indoor localization technique results shown that the effectiveness of the techniques to be implemented in a company to improve the efficiency in the production line.