Functions
Accessing Functions | Keyboard Access
Functions are the low-level building blocks of the R/3 System. They provide the elementary business actions like creating or editing a document or printing a report. Functions differ in their complexity. Some functions perform only very simple tasks. These are, for example, the editing functions cut, copy or paste. The elementary navigation functions for moving from one screen to another are also simple functions. Other functions, however, may initiate complex business processes. As we already stated, while the menu tree provides the skeleton for an R/3 application, the functions fill it with flesh.
One important aspect of functions is to standardize them. This helps to limit the possible universe of different functions in the R/3 System to an overseeable number. These standard functions have a predefined behavior that users will be able to learn and understand. Thus, standardization of functions allows users as well as developers to use these functions in a specified manner and with a specified meaning. Standard functions are an effective means to make the R/3 System consistent.
For the R/3 System more than 50 standard functions have been defined. These standard functions are widely used in R/3 applications. So, users feel familiar with them and remember their meaning as well as how to access them. That is, they know where to look for them in the menus and what they are good for.
For an overview of the R/3 standard functions, their names and access have a look at the SAP Reference Lists on the SAP User Experience Community. They tell you a function's function key, access character, and way to assign a pushbutton to it.
Source: SAP R/3 Style Guide