Resumo:
The machining can be considered a great process in the industry. Its development
accompanied the evolution of the production engineering and product engineering. In
consequence new tools and new machines were created. In this context, the heavy machining
process appeared to assist of a private market, generally composed by pieces of great
dimensions, such as the components for the energy plants and steel plants. Nowadays the
companies need an aggressive posture to reduce costs and to increase the quality of your
products. However, to reach these objectives, it is necessary to know the processes, their
operational times and their costs. This work presents, for a heavy machining processes, the
influence of the unproductive times on the total time of production. And the influence of the
unproductive costs on the total cost of production. Thirteen pieces were analyzed in heavy
machining processes, in a total of 1776 hours of production. The application of the techniques
of sensibility analysis and simulation revealed three main factors of unproductiveness:
machine preparation, tools preparation and maneuver time. When considered the involved
costs, the study revealed a small alteration in the main causes: machine preparation costs,
tools preparation costs and the maintenance costs.