In previous versions of OS/2, the user shell was designed to conform to the 1989 SAA CUA Graphical Model. The Workplace Shell of OS/2 Version 2.0 now reflects the 1991 SAA CUA Workplace Environment.
In May 1989 (as part of the OfficeVision* announcement) IBM announced an extended role for the programmable workstation in the SAA environments. Part of this announcement, known as CUA 89, introduced the Workplace extension to CUA's graphical model. This workplace environment defined a more object-oriented approach to interaction with the system through direct manipulation of objects.
In September 1991 IBM announced extensions to the SAA architecture. Included in these extensions was CUA 91, an orderly growth from CUA 89. CUA 91 enhances the object-based user interface defined in CUA 89. Rather than interacting with applications, users interact with objects which represent the inputs and outputs of their jobs. The Workplace Environment is based upon the metaphor of the user's working environment, with objects such as forms, letters, an address book, printers etc., represented on an electronic desktop using graphical symbols known as icons.
CUA 91 has an increased emphasis on direct manipulation; that is, the manipulation of workplace objects through their representative icons on the desktop. This allows the user to concentrate more on the task at hand, and less on the mechanism that must be employed. The user is presented with a number of icons, each of which is a pictorial representation of the real underlying object which in fact controls the data.
CUA 91 also introduces a number of new controls. Perhaps the most noticeable of these is the notebook control. This control allows an application to present a multi-page dialog (for example, a pad of blank forms, a log or register, or a set of reference notes). The notebook control provides a more meaningful way of providing an electronic metaphor of complex objects than a series of dialog boxes or other secondary windows.
Extensive documentation for CUA 91 exists in the form of the IBM Systems Application Architecture CUA Advanced Guide to User Interface Design and the IBM Systems Application Architecture CUA Advanced Interface Design Reference. However, the best way to appreciate the spirit behind CUA 91 is to view the demonstration "The CUA Vision - Bringing the Future into Focus." This demonstration is based on a version of CUA beyond CUA 91. It does, however, bring home very vividly the essence of CUA 91: pervasive interaction with workplace objects (represented by icons and other graphical controls) through direct selection and manipulation. As will be seen in this demonstration, the user is not aware of applications as such. Business processes are completed as a result of a natural and meaningful interaction with objects.