Balance between the costs of automation

Businesses often decide between using automation and labor in production. An automotive environment may have high fixed costs and low variable costs, and an industry that utilizes manual labor for production will have low fixed costs and high variable costs. How would you describe the balance between the costs of automation, or fixed costs, and the costs of labor, or variable costs? How has technology changed the balance between automation and labor? What type of industry benefits the most from technological innovation?