The drive to cut costs and rise productivity won't end soon. If anything, competition could bolster up as the Japanese and Europeans, facing continued weakness at home, remain harder to the industrial world' s strongest economy. American business has responded to intensifying competition by investing immense sums in computers-- both to automate the factory and to reengineer the office. That trend won't change. Though purchases may slow from 1993's stupendous 40% growth rate, computers will heat the driving force in the business-equipment market. High-tech investment by telecommunications and entertainment companies gearing up for the electronic superhighway may also sell investment.