Dell became the master of process engineering and supply chain management. It spent less on R&D than did Apple or Hewlett-Packard, but focused its spending on improving. its manufacturing process. (Dell spent 1% of sales on R&D versus the 5% typically invested by other large computer firms.) Instead of spending its money on new computer technology, Dell waited until a new technology became a standard. Michael Dell explained that soon after a technology product arrived on the market, it was a high-priced, high-margin item made differently by each company. Over time, the technology standardized-the way PCs standardized around Intel microprocessors and Microsoft operating systems. At a certain point between the development of the standard and its becoming a commodity, that technology became ripe for Dell. When the leaders were earning 40% ro 50% profit margins, they were vulnerable to Dell making a profit on far smaller margins. Dell drove down costs further by perfecting its manufacturing processes and using its buying power to obtain cheaper parts. Its reduction of overhead expenses to only 9.6% of revenue meant that Dell earned nearly $1 million in revenue per employee-three times the revenue per employee at IBM and almost twice HP's rate.