As I was once again forced to use one of the most horrible software products I have ever laid eyes on, it occurred to me that it's worth repeating one of my favorite mantras, even at the risk of sounding like a broken record (do any of you kids even know what that means? ;-) --> Simplicity in your design is your goal. If you can get to the point where the interface "disappears" and the user can just get in the flow and do their work, then you've really got something there.
So many of the things we use on a daily basis, both software-based and not, are way more complex than they have to be. We're all too busy to be wasting time with complicated systems, yet in many cases this has become the norm. As an example, I recently had to replace my kitchen blender. A trip to Williams-Sonoma quickly became an exercise in frustration. Most of the blenders had so many features and functions that I was surprised they didn't contain a microchip or two. Multiple buttons, gadgets and add-ons all to accomplish a single purpose...blend some stuff up! In the end, I found the perfect blender for me...a replica of an old model that has a single switch for two modes: hi and low. When I want to blend something, my choices are simple and I can immediately get down to business without thinking about all the different options I have. It's actually pretty liberating to simplify like this. We use an old-fashioned manual can opener in the kitchen too. It works wonderfully and we don't ever have to worry about it breaking. Stuff used to have a singular purpose and did it without a lot of fuss and choice. I use this idea as the guiding principal in the work I do.
Now trying to compare a kitchen blender to enterprise software is a bit of a stretch, but I think you understand what I am getting at. There is quite a paradox at work when we give our users too many choices in our applications. When faced with a lot of choices, we actually find it harder to choose because we are wired to evaluate all of the potential options. Have you ever felt paralyzed looking at your To Do list because there were so many tasks you didn't know where to begin? This same feeling of overwhelm hits a lot of our users when they are faced with a complex interface, especially one that provides them with many paths to go down.
If you are building a business-facing application that will be used by actual humans, then you have a targeted objective you are trying to achieve. The interface should facilitate this process and it should provide the path of least resistance to do so. If it's easier to do it the old-fashioned way, users will ignore your app. It's important to focus on your interface so that it gently guides the user to their objective without getting in their way. One way to completely fail in this regard is to provide too many choices and ways to accomplish the same task.
So how can you practically apply these ideas? Evaluate each and every element you place on the screen. Make features and functions fight for their lives. If an element does not have an explicit reason for being on the screen at the time a user is performing a particular task, then it shouldn't be there. Keep controls very simple and related to the context the user is currently in. Generously use whitespace.
These basic ideas seem to be simple common sense (and they are!), but I've seen far too many applications that break these rules. I don't know a single person that wishes their life was more complex than it already is. Keep the concept of simplicity at the forefront of all of your designs and I promise that your users will thank you.