Before we can discuss why a company might want BPOS, we first need to cover what it is. The Business Productivity Online Standard Suite, the most common version of BPOS, is comprised of four primary applications: Exchange Online, SharePoint Online, Office Communications Online, and Office Live Meeting.
Exchange Online is based on Exchange Server 2007. To the client (user), the application looks and feels exactly like Outlook 2007, so there’s none of the webmail clumsiness common in apps such as Gmail or Yahoo! Mail, nor is there time wasted having to learn a new set of features, menus, and so on. Users familiar with Outlook know how to run Exchange Online from the second they meet it. Each mailbox gets 5GB of capacity, but admins can tweak this up to 25GB under certain conditions. If a company has 10 licenses and each user is allocated 5GB, the company has a total of 50GB to divide up how it sees fit. For instance, two users could get 15GB each while the remaining eight users get 2.5GB each.
Having Outlook as a Web app is cool in its own right, but there are more benefits behind the scenes. Messages get scrubbed for viruses and spam via Microsoft Forefront before they ever hit users’ inboxes. Microsoft also handles daily backups and deleted item retention—both for messages and entire mailboxes. Microsoft also isn’t shy about trumpeting its 99.9% uptime service level agreement (SLA), and backs this guarantee up with cash, not credit as other service vendors do. This SLA is no small thing. Enterprise servers are typically governed by “three-nines” or “four-nines” uptime requirements. Desktop systems, on the other hand, often have 95% uptime or less, and for every worker to lose 5% of his or her productivity throughout the year just because of system glitches is unacceptable to any responsible, productive business.
Does shifting to Exchange Online (or any of the other BPOS services) eliminate downtime? Of course not. You’re still working on traditional desktop hardware, not fire-tested server gear costing five times as much. Statistically, desktop hardware will fail more often than server hardware. But part of that sub-95% statistic has to do with instabilities caused by how desktops are configured, applications overlap, and so on. By simplifying the configuration through moving to a cloud-based model, chances are that overall uptime will improve. And, with cloud-based apps, a user can easily move to another computer while their computer is being fixed.
To its credit, Microsoft hasn’t used BPOS as a club to beat everyone into using its own related products. The entire suite will run on Mac OS X 10.5 as well as Windows XP (Professional or Tablet) and Vista. Applications will run on Internet Explorer 6 or later as well as Firefox 3 or Safari 3.1.2. For Exchange Online specifically, there’s also mobile device compatibility on phones running Windows Mobile 6, the Nokia E and N series, BlackBerry devices, and even Apple's iPhone with 2.0 firmware.
You might notice that Microsoft also recommends running Outlook. This may seem like a case of double dipping, but it’s only a recommendation, not a requirement, because with this users can have offline access to email (as well as SharePoint documents and prior IM chats) when a live browser session isn’t available.