The quality is becoming an increasingly important factor for any business, once a quality product is a more competitive product. This paper aims to draw the sigma level profile that a process reaches a year by analyzing the capacity. This generates a forecast of failure and costs allowing therefore a better production management. The study was applied to fault data in the electric glass mechanism of cars of dealers. The expected average cost of company in maintenance decreases by about 70% if the production process is maintained at a level of at least three of sigma quality.