Thin-client, or server-based computing, emerged in the late 1980s with Citrix Systems WinView, a multiuser product for IBM OS/2. By the late 1990s, this architecture took a 3 percent toehold in the networking market. We first looked at this as a passing fad, but by the end of the century server-based computing had a leg up with 23 percent share and found a place in most Fortune 100 companies. Today, server-based computing is a mature industry that includes many thin-client devices with network- and bandwidth-management solutions and wireless-connectivity options.

Embracing Thin Clients

A thin client today ranges in price from $400 to $800 without a monitor. We could compare that with a sub-$500 PC, but this is not the standard enterprise purchase. Rather, enterprises seek PCs with staying power. They purchase fully loaded PCs from name-brand vendors, priced at $1,200 to $1,500 each. According to the Gartner Group, this initial price is only 20 percent of the TCO over the life of the PC. The remaining 80 percent comes from the time, labor and materials to support, maintain and upgrade it. A thin client has little or no overhead for maintenance and support.

If economics were the only factor in moving to server-based and thin clients, we would all have a lot more room on our desktops. But economics has been outweighed by enterprise politics and the PC industry. Many enterprises have different departments with autonomous budgets that include separate IT departments. These distributed-computing environments resist a centralized, server-based architecture. Also, enterprise users often doubt network reliability and demand local resources so they can continue working during outages. Finally, the PC industry has weaned us all on the usability and idea of more, better and faster processors on our desktop. Thin clients won't replace PCs, but they do have a place in the enterprise to provide productive, cost-effective solutions.

For instance, thin-client devices can replace old, dumb terminals connected to host systems. Although easy to maintain, terminals have limited, character-based user interfaces, and often use legacy serial connections running with an Ethernet infrastructure. Replacing these with PCs is overkill where PC functionality would be limited to terminal emulation. Thin clients provide terminal-emulation software resident in ROM and can use existing Ethernet infrastructure.

Where PCs are not used to their full potential, thin clients can provide a cost-effective alternative. Thin clients make sense for enterprises running only a few applications that are not processor-intensive. Task-based users can benefit from thin-client devices for location-independent access to consistent desktop configurations. By reducing the complexity of accessing computer resources, you increase user productivity. Thin clients also are popular as point-of-sale and kiosk devices on shop floors, in libraries and anywhere a single application is available that requires a reliable and sturdy platform.

Enterprises spend exorbitantly to support and maintain PCs. They purchase software packages to gather asset inventories, maintain common desktop configurations and deliver applications. Yet the time it takes to upgrade or install applications to all enterprise PCs is measured in days, weeks -- even months. With server-based computing, applications are installed, maintained and upgraded on central servers; the deployment of an application to thin-client devices can be measured in minutes and hours.