In an advanced workplace strategy, the tracking and measurement of desks or workspaces assigned to people who are always in the office is known as permanently-assigned space. This differs from space temporarily assigned to mobile workers who are often working outside the office. The latter is known as hoteling. The measurement and management of permanently-assigned space and temporarily-assigned or hoteling space provides almost the highest levels of efficiency and sustainability. Using reverse hoteling to utilize permanently-assigned space on the few days when those workers are not in the office maximizes efficiency, cost reduction and sustainability.