This paper presents a study about fatigue recovery time assessment processes in work activities. It came about due to a demand presented by an automotive industry giant, in need of updating existing cycle time sheets and TAKT time parameters. The company decided to hire an Ergonomics Laboratory with ties to a major Brazilian University in order to evaluate current conditions and establish a new method to either calculate recovery times or validate existing assessment criteria, based in the ergonomics evaluation of the work activities. It is clear that there has been evident evolution in the industrial sector in the past two decades. It brought up fast modernization of industrial processes, not only in production but also in terms of management systems. Due to improved computer and robotics systems, combined with overall operational advancements - like the use of lighter hand tools and more effective hoist systems - most work activities have had its physical effort requirements reduced in the past decades. Thus, compensation factors built into production times need to be reviewed in order to avoid unnecessary costs associated to them. By using ergonomics considerations, we prevent simply removing the physical variables built in rest time calculations without taking on account, for example, additional cognitive load represented by the use of more sophisticated pieces of equipment.