According to an example of the present disclosure, a system is disclosed. The system comprises at least one sensing unit and a robotics engine in communication with the at least one sensing unit. The at least one sensing unit detects stock information associated with an item. The robotics engine performs a trend analysis based on the stock information collected over a predefined duration of time, and determines a threshold value based on the trend analysis. Furthermore, the robotics engine generates an alert when the stock information is below the threshold value, and selects a vendor based on one or more predefined parameters. The robotics engine also generates an instruction to obtain the replacement item from the selected vendor for replenishing the item in an inventory.