One fun thing about being an engineer is watching the rapid advances in technology. What was James Bond yesterday is ho-hum today. (Check out some "state of the art" technology in old movies.)But we sometimes lose sight of that business processes and requirements change, too. Here are a handful of significant shifts in business processes and requirements that I've noticed over the years:Consolidation. As companies continue to cut costs, they're increasingly centralizing and consolidating shared functions, services and infrastructure. In a recent Nemertes Research benchmark, we found that 54% of participating companies had consolidated data centers in the past 12 months, and another 57% planned to further consolidate in the next 12 months. IT departments are increasingly centralized, partly resulting from the efforts of CIOs to retake control of overall IT operations.Geographic dispersion. At the same time that infrastructure's consolidating, individual employees are increasingly geographically distributed. Nemertes benchmarks have consistently documented that roughly 90% of employees work somewhere other than headquarters, and the number of virtual workers (employees who work somewhere other than their peers and\/or supervisors) increased ninefold over the past five years.Extreme availability. Another business trend is decreasing tolerance for downtime or even impaired performance. Five or 10 years ago, companies were generally somewhat tolerant of downtime (at least in certain industries). But an unintended consequence of some of the disasters and crises of recent years is to raise the bar for availability. With well-designed business-continuance plans, companies can maintain availability in the face of disasters - and once something is proven possible, it becomes mandatory.At the same time, expectations for application performance at remote and distributed offices continue to ratchet up. Companies expect the same response time regardless of whether a user's down the hall or around the globe from the server on which the application is running.Increasing agility. Finally, companies increasingly need their infrastructure to enable near-instantaneous responsiveness. If a new market opens in Texas or Bangladesh, the infrastructure should be in place tomorrow.These expectations make the WAN more important than ever. The combination of infrastructure consolidation and employee dispersion means that servers are increasingly remote from users. So if the network goes down, so do the apps - which is less acceptable than ever, thanks to the expectations of increased availability.Thus, WANs need to be designed and managed with these requirements in mind. Network architects should think in terms of deploying application-acceleration tools, which help ensure performance even across less-than-perfect networks. Network architects also should design in availability and redundancy from the start. They should consider services that can be rolled out quickly, such as IP VPNs. Enabling effective management of remote sites, users and applications is increasingly key.The bottom line: Effective WAN architecture is more important than ever, particularly in the light of changing business needs.