I am often asked about the difference between decision support systems and decision management systems. This is an interesting topic and one that is central to the value proposition of decision management systems so I thought I would revisit it.
All decisions involve a choice, a selection of a course of action from a set of alternatives and generally result in an action being taken, not just knowledge being added to what’s known. Decision Management Systems, unlike Decision Support Systems, are focused on taking or recommending this action. Decision Support Systems are focused, obviously, on helping (supporting) someone make the decision, not necessarily on the actions to be taken. This distinction is critical to the difference between the two classes of systems. If you want or need a system to make a decision (because there is no human present as in a web site or kiosk, because there is no time for a human intervention or just because the people available don’t have the skills to make a good decision), you need a Decision Management System. If you have the option, though, to do either it is worth considering 5 additional ways in which the two kinds of system differ:
- Defined and known actions
In general the available actions, the range of possible actions from which an action is selected, is implicit in a Decision Support System, with the user having an idea of the range of options even though this is not generally coded into the system. In contrast a Decision Management System has an explicit, defined, known set of possible actions coded into it. This means that the outcome is more predictable, more likely to be within expected bounds, critical for operational decisions. - Expertise and judgment
While both Decision Support Systems and Decision Management Systems apply expertise and judgment, Decision Support Systems rely on the user to have experience and apply their own judgment. This means that decision support works better for strategic and management/control decisions where the user is likely to have some significant experience and that decision management is a better approach for operational decisions. - Policies and regulation
In a Decision Support System the user is generally responsible for reading, understanding and applying the policies and regulations relevant to the decision. In contrast a Decision Management System uses business rules or other decision logic management capabilities to embed the relevant policies and regulations and so ensure the system is compliant with them. When compliance is critical, then, a Decision Management System is going to be more reliable. - Data analysis
In a Decision Support System information is presented to a user so they can analyze it. Increasingly this means using advanced visualization and other approaches to both summarize more data and make it more obvious what patterns are in the data. In contrast a Decision Management System cannot rely on visuals but must instead apply analytics programmatically. This means using the output of data mining and predictive analytic techniques, for instance. What this means is that while a Decision Support System might help a user see the likely futures implicit in their data and so act appropriately, a Decision Management System will make any decision in the context of mathematical probabilities. - Repeatability
In the final analysis a Decision Support System is not designed to produce a repeatable approach to decisions, at least not a completely repeatable one. The user has some degree of freedom they can apply to each decision, giving more flexibility but at the cost of less consistency and repeatability. A Decision Management System always applies the same logic, uses the same analysis techniques and so makes a repeatable decision.
Of course many scenarios involve a blended approach, with a Decision Management System rapidly determining a small set of possible actions, taking the best if this is clear and presenting the set of actions in the context of a Decision Support System for a user to resolve tricky situations for instance.
In find the graphic on the right to be an effective tool when it comes to deciding on the right balance between the two systems. In general the more strategic a decision and the less often it must be made, the more value a Decision Support System offers. For more repeatable, operational decisions the value shifts inexorably towards Decision Management Systems.
