I was thinking about the different roles mobile devices play I our business lives while watching one of those new Microsoft iPad attack commercials for the twelfth time the other. In this version, an iPad Mini’s Siri tries to talk to someone using a 7 inch Windows tablet. Or maybe it’s talking to the Windows tablet which is strange. Part way in, the Windows tablet user starts playing Halo. Halo? Do customers really buy a tablet to play Halo on? I tend to think not. A business user is even less likely to do that since that’s simply not how people view these devices.

There is a tendency to talk about mobile devices as if they were a single entity. Software vendors especially talk about their “mobile” strategy and not their smartphone and tablet (or smartwatch) strategy. That’s unfortunate since that’s an attitude that will eventually lead to some pretty bad software. It’s not just the screen sizes and limited hardware that are different between devices and desktops. It’s true that different screen sizes drive user interface design choices and the limited hardware means making hard choices about certain types of features. These are small compared to the differences in the way people use these devices. What a business professional is trying to get out of a tablet versus a smartphone, or desktop for that matter, should be the bigger driver.

Here’s how I view the different ways we use these devices:

• Smartphones are for communication. Yes, we access all types of information on a smartphone but we focus the most on interactions with other people. Social networks both corporate and personal, email, text, voice and video calling, contacts and calendars – the stuff of business relationships – are how we spend our time on a smartphone. While there is a lot of attention on new location-based services that leverage the portability and GPS in a smartphone, that’s not what business users do. Smartphones are for interacting with people.
• Tablets are a view into the cloud. Let’s face it – tablets are a convenient and portable way of accessing cloud applications. They allow us to interact with data somewhere else without hauling around a laptop. Most business users read documents, view reports, look at graphs, show presentations, and perform simple workflow operations in our cloud based enterprise applications on a tablet. It gives that view into corporate data without hurting our backs. The fact that we can read email and access corporate communications is gravy not the meat.
• Desktops and laptops are for real work. Intensive work such as writing, creating spreadsheets, data entry, and graphics, require the full sized physical keyboard, 22 inch plus display, big chunks of memory, massive hard drives, graphics co-processors, gigabit Ethernet network connectivity, and serious processing horsepower of a regular PC or MAC with a full service operating system. Tablets and smartphones are great for what they do but have limited resources even when running an application in a browser. Desktops and even laptops are not limited by the power and portability constraints of mobile devices.

This is why more and more business users regularly use three or more devices. None is a replacement for another. Just because something used to be done on a desktop PC or phone in the past doesn’t mean it was optimal. You can make Skype calls from your desktop after all but is that the best way? A smartphone is designed for voice communications and you don’t have to go looking for a set of headphones with a microphone.

The reason this matters so much is because the one size fits all application model is falling apart again. The ability to deliver an enterprise application in a browser was great for application developers, cloud or otherwise, since they no longer had to write code for lots of operating systems. Unfortunately, we are back to that situation but not because of form factors or operating systems, though they are part of the problem. Instead, it’s because business people want to use different devices differently. They want to leverage unique capabilities more than overcome limitations. At the moment, that means at least three versions of everything, each tailored to the way tablets, smartphones, and desktop applications are expected to behave.