In the last years, capital investment in machinery and equipment has increased. This requires that better maintenance strategies to keep equipment working under optimal conditions be enabled. Since incorrectly performed maintenance or the lack of it can provoke extensive losses, this topic becomes a critical issue. The two main maintenance techniques found in the literature are Total Productive Maintenance (TPM) and Reliability-Centered Maintenance (RCM). TPM is a maintenance program aiming to discover the hidden capacity due to ineffective performance. On the other hand, RCM is an approach focused on the equipment right operation at the minimum amount of maintenance and downtime. TPM and RCM have to be tied to the company's economics in order to quantify benefits in terms that management can understand. One of the approaches widely used when measuring the economic side of a service of manufacturing process is the Cost of Quality (COQ) through the PAF model. In this paper, we define a COQ model for maintenance, based on the key characteristics of TPM and RCM. The model uses the PAF+L categories where opportunity costs are included along with prevention, appraisal and failure costs. This model will assist researchers and practitioners to calculate the economic benefits of implementing TPM and RCM. Copyright, American Society for Engineering Management, 2012.