Abstract: The present disclosure relates to a method of detecting an indication of a tightening tool deteriorating in tightening performance, and a control device performing the method. In a first aspect, a method of detecting an indication of a tightening tool deteriorating in tightening performance is provided. The method comprises acquiring at least one set of observed values of a torque having been applied by the tightening tool to an object to be tightened over a first time period, determining whether or not an overshoot metric of the observed values in the at least one acquired set with respect to a target torque exceeds a predetermined overshoot threshold value, and if so providing an alert that an indication of performance deterioration of the tightening tool has been detected.