Product Information Quality (PIQ) is critical in manufacturing enterprises. Yet, the field lacks comprehensive methodologies for its evaluation. In this paper, the authors attempt to develop such a methodology, which is called Activity-based Measuring and Evaluating of PIQ (AMEQ) to form a basis for PIQ measurement and evaluation. The methodology encompasses a road map to measure and improve PIQ, an indicator system based on characteristics and logic-temporal sequences of processes, and a set of models to quantificationally describe, operate and measure the designing and manufacturing processes of mechanical product information. The methodology is illustrated through a business case. The results of the methodology are useful for determining and reviewing the best area for PIQ improvement activities.