Issue-Based Information System (IBIS) was invented by Werner Kunz and Horst Rittel as an argumentation-based approach to tackling wicked problems – complex, ill-defined problems that involve multiple stakeholders.
To quote from their original paper, "Issue-Based Information Systems (IBIS) are meant to support coordination and planning of political decision processes. IBIS guides the identification, structuring, and settling of issues raised by problem-solving groups, and provides information pertinent to the discourse...".
Subsequently, the understanding of planning and design as a process of argumentation (of the designer with himself or with others) has led to the use of IBIS as a design rationale.
The basic structure of IBIS is a graph. It is therefore quite suitable to be manipulated by computer.
The elements of IBIS are issues (or questions that need to be answered), each of which are associated with alternative positions (or possible answers). These in turn are associated with arguments which support or object to a given position (or another argument). In the course of the treatment of issues, new issues come up which are treated likewise.
Issue-Based Information Systems are used as a means of widening the coverage of a problem. By encouraging a greater degree of participation, particularly in the earlier phases of the process, the designer is increasing the opportunity that difficulties of his proposed solution, unseen by him, will be discovered by others. Since the problem observed by a designer can always be treated as merely a symptom of another higher-level problem, the argumentative approach also increases the likelihood that someone will attempt to attack the problem from this point of view. Another desirable characteristic of the Issue-Based Information System is that it helps to make the design process “transparent.” Transparency here refers to the ability of observers as well as participants to trace back the process of decision-making.
IBIS is used in issue mapping, an argument visualization technique related to argument mapping. It is also the basis of a facilitation technique called dialogue mapping.