In writing Cloud Standards, I spent more time than I expected working on a good description of the distinction between functional and managerial interfaces to services. I referred to management and functional interfaces recently in a blog on the CA Cloud Storm Chasers site. I’ll say a little more here.
Functional versus managerial are clearly separate in my head, but stating the difference succinctly is to not so easy. I’ve got it down to “a managerial interface manages the delivery of a service to the consumer and a functional interface delivers the service functionality.” I say much more about it in the book.
Distinguishing functional from managerial is important because standardization of managerial interfaces plays differently than standardization of functional interfaces.
Word processing functional interface
There is no limiting or predicting functional interfaces as they change and respond to technology and consumer taste. For at least a decade, word processors sported a narrow strip menu on top of a big more-or-less WYSIWYG (What You See Is What You Get) entry pane. There were minor variations between the contenders, but that was what a word processor looked like.
If it isn’t broke, don’t fix it, right?
So what did the leading word processor development team do to their 2007 version? They switched to a ribbon menu at the top. Not a big change, but enough to generate confusion and grumbling from experienced users. New functionality? Not much. I certainly uttered a few choice words about gratuitous change when the CA IT department installed a copy on my work laptop. But that’s the way with functional interfaces. Somebody always has a sleeker, jazzier idea.
And that is as it should be. A few years later, I am used to the ribbon and have grown to prefer it. When I switch to an open source word processor on Linux, I miss that once-hated ribbon. Redmond scores! I hope the ribbon is not tied up tightly in patents because I want the open source word processors to adopt it. Then I can install a ribbon menu word processor on my Linux boxes.
Managerial interfaces
Management interfaces are different. Often they are APIs. They tend to change only when technology changes and they are often held in line by standards organizations that intentionally tamp down variations that do not confer clear benefits. This prevents unnecessary breakage of other applications that use the managerial interfaces. We are less likely to see the equivalent of an apparently quixotic change to ribbon menus on the managerial side.
Distinguishing functional from managerial encourages both innovative functionality and stable integration. It makes life easier for everyone.