This story illustrates how my personal experience led me to conclude the fewer mouse clicks, the better. But this is nothing more than a subjective opinion. The world loves mice. I may be the only person in the world complaining about too many mouse clicks. However, I recently saw some hard data from an internal IBM human factors study that empirically demonstrates that the mouse is the slowest of several common data entry devices.
Human factors is an area where applying the systems perspective to engineering is key.
The systems perspective requires looking at all parts of a system throughout all phases of system development and deployment and questioning how a system will be used. For human factors considerations, this means performing operational scenarios early in the system development to determine human interaction with the system, specifying human factors requirements, reviewing designs for human factors impacts, and modeling the user interface in mock-ups. This activity should continue through system verification to validate assumptions, scenarios, and data. Nonetheless, it is a highly likely operational scenario for that particular tool. Engineers have become better at remembering the human in the system.