On the process route for stainless steel grades the scope of melting materials used is growing. In the electric arc furnace which melts down a prerefined metal for the converter or the vacuum system, the share of alloyed scrap varies from 0 to 100 % as a function of the steel grade to be produced. Therefrom the amount of ferroalloys which are difficult to be melted down results from the specified steel analysis. Depending on the market situation and availability in some regions it may be useful to charge as much liquid hot metal as possible as the iron carrier. Depending on the production programme the upper limit of this material which can be melted down easily is in the range of 50 to 60 %. This paper reflects commissioning experiences with regard to the performance guarantees of various stainless steel plants.