Back-of-the-envelope Action Analysis

This method can be performed quickly, becaused it uses fewer and compound actions, like "select cut from the edit menu, instead of "take your hand of the keyboard and move it to the mouse; locate the edit menu on the screen; move the mouse pointer to the edit menu; ..."

Each action is assumed to take "a few" (2 or 3) seconds.
(This may be 4 or more or even 10 on a bad day, before morning coffee or after an "allnighter".)

The following questions can be answered:

This method of action analysis is especially useful for deciding whether or not to add more features to an interface: adding features means that the user needs to decide between more possible actions. This results in slower performance for routine tasks.

As subsequent versions of an application become more sophisticated and thus slower to learn and use, newer and simpler applications may take over a significant market share.