Monday the employee didn't arrive. Tuesday neither. Wednesday nobody answers their cell phone anymore. By Friday, the employer is convinced that they "resigned" and sends a request to terminate them from the IMSS. That move, done like that, is the origin of most of the lawsuits for unjustified dismissal that I see happening in Mexican restaurants and workshops. Repeated absence without notice can indeed end in termination without liability for the employer, but only if it is handled the right way.