(55)In order to protect consumers against the risk of extended delays, any repair or replacement should be successfully completed within a reasonable period of time. What is considered to be a reasonable time for completing a repair or replacement should correspond to the shortest possible time necessary for completing the repair or replacement. That time should be objectively determined by considering the nature and complexity of the goods, the nature and severity of the lack of conformity, and the effort needed to complete repair or replacement. When implementing this Directive, Member States should be able to interpret the notion of reasonable time for completing repair or replacement, by providing for fixed periods that could generally be considered reasonable for repair or replacement, in particular with regard to specific categories of products.