Real-time monitoring system µPMU hardware and software design Error and phasor estimation Computational time minimization This article presents a roadmap for distribution grid µPMU hardware and software design consideration and implantation to ensure high performance within limited computational time of sampling frequency 512 samples/cycle. A proposed 12 channels, multi-voltage level µPMU hardware and rules of voltage and current transducer, analog filter, analog-to-digital converter, sampling rate definition, and PCB design and selection are presented. From the software view, software minimization procedures are implemented to reduce the estimation time of the proposed µPMU to 18 µsec under high sampling frequency operation. Additionally, error estimation and compensation are used to ensure robust performance, while the computational burden of the error compensation stage is reduced by Taylor series linearization. The proposed µPMU is designed to provide traditional phasor, frequency and harmonics measurements besides a point-on-wave under dynamic operation mode. The proposed device is tested under IEEE Std C37. 118.1 and 118.2 and showed accurate phasor estimation up to 0.03% for the magnitude and angle accuracy up to 0.0036 o , while the frequency is estimated with maximum variation of 0.032% under dynamic operation.