Automation of office work constitutes a new growing appl ication of information systems. The original characteri stics of an Office Information System (OIS) in comparison with a conventional information system imply the need for devel opi ng new design methodol ogies and model s, which are cl assified and discussed in this paper. OIS are not just document management systems (or word processing systems), 1.e., they do not consider only, or mainly, static aspects of data: they are in fact more general information systems where documents are only one of the many elements of the system. In addition, while conventional IS are often applied to support operational activities, office work shows many different facets, and therefore it is not reduci bl e to a set of operatl onal activities. Correspondi ngly, whil e the main phases that are commonly recognized in the design of a conventional IS (such as requi rements analysis, requi rements specification, logical design, optimization and implementation, system eval uatl on and . modification) can be transferred al so to OIS design, the , conceptual models for requirements specifications, on which the early design phases are based, should instead be changed in order to allow the specification of particular aspects of an OIS. Such aspects include new functionalities, such as filtering of data, reminding of activities to be performed, scheduling of manual and automatic activities, and communication; some specific types of data are also needed in an OIS: groups of data (documents and dossiers), unstructured and incomplete data, sophisticated handling of time, and of compl ex situations, distributed data, office workers roles. Other particular aspects are related to the fact that an office system is intrisically evol uti onary, and with the usage of the system: highly interactive, integrating different functions, requiring great flexibility with possible interruptions of tasks and with a high number of exceptions arising during the work.