Interpretive Structural Modeling

Interpretive Structural Modeling(ISM) is a computer-aided method for developing graphical representations of system composition and structure. It was invented by John N. Warfield in the early seventies. The application of ISM results in the identification of relationships among specific items, which define a problem or an issue and the end result is an influence map (in the form of a tree structure) which reflects the consensus of all participants of the dialogue. A systematic application of graph theory is used to visualize and explain the complex pattern of contextual relationship among a set of variables.

An ISM application starts with the identification of the variables, relevant to the issue by asking the stakeholders (i.e., participants of the dialogue) to submit first single statements, and later full clarifications of what they consider a response to a well phrased Triggering Question. Then a contextually relevant subordinate relation has to be decided. Example:

If we make progress in resolving Challenge X
Would that make the resolution of Challenge Y SIGNIFICANTLY easier?

Having decided the contextual relation, a structural self-interaction matrix (SSIM) is developed based on pairwise comparison of variables. The SSIM is converted into a reachability matrix (RM) and its transitivity is checked by the algorithm. A process called Transitivity Embedding is conducted to fill-in connections between items that can be deferred. A number of matrix transformations is performed, which results to the construction of an Influence Map.

References

• Warfield, J. N. (1973). Participative methodology for public system planning. Computers & Electrical Engineering, 1(2), 187–210.
• Warfield, J. N. (1974a). Developing interconnection matrices in structural modelling. IEEE Transactions on Systems, Man & Cybernetics, 4(1), 81–87.
• Warfield, J. N. (1974b). Toward interpretation of complex structural models. IEEE Tranactions on Sys- tems, Man & Cybernetics, 4(5), 405–417.
• Warfield, J. N. (1976). Societal systems: Planning, policy and complexity. New York: Wiley.
• Warfield, J.N., and Christakis A. N. (1987). “Dimensionality.” Systems Research and Behavioral Science 4.2: 127-137.
• Warfield, J. N. (1982). Interpretive structural modeling (ISM). In S. A. Olsen (Ed.), Group planning & problem solving methods in engineering (pp. 155–201). New York: Wiley.
• Warfield, J. N. (1994). A science of generic design: Managing complexity through systems design. Ames: Iowa State University Press.
• Warfield, J. N., & Cardenas, A. R. (1994). A handbook of interactive management. Ames: Iowa State University Press.