Optimization of reliability requirements from manufacturer´s point of view

Nearly all consumer and industrial products are sold with warranty. This has important cost implications for the manufacturer because every warranty presents additional costs for him. The article analyses dependencies among cost price, warranty cost and product reliability. According to these analyses, the article presents two methods of optimisation requirements on the reliability of products. The first method makes it possible to specify the requirements on reliability level, which will lead to the minimal manufacturer´s costs (research, development, production and warranty costs) if the length of the warranty period is firmly given. The second method makes it possible to specify the requirements on reliability level, which will lead to the maximal possible length of warranty period, if the manufacturer´s costs are firmly given