What is decision modeling ?

There are some standard business processes that every organization performs daily.

Due due to their frequency and importance, it is vital that these business processes remain efficient and effective.

these type of business processes are ideal for improvement especially if those improvements can help identify and eliminate bottlenecks.

To improve these processes, it may be necessary to streamline and automate some steps in the process.

Steps in the process such as approvals, are ideal candidates for automation and a decision model can be used to identify these steps.

Decision models are visual representation of a process which show how data and knowledge are merged together to make a particular business decision.

The model is connected to business processes, business rules, resources and performance measures in the organizations.

For example: an example of a behavioral rule is : if the customer’s billing address matches the credit card details provided then the order should be processed.

Decision models can also be used for both simple and complex decisions.

Simple decision models use a single decision table or decision tree to show how a set of business rules work on a set of data components to produce a decision.

While a complex decision has numerous simple decisions combined into one.

There are some elements of decision modeling which need to be included to make it complete and they include:

1. Types of models and notations:
All decision modelling approaches involve three main elements, which are:

  • decision.
  • information.
  • knowledge.

But there are different ways in which a decision model can be created.

For example a decision table is used to show all the business rules needed to make a decision.

Here are a few examples of different decision modeling techniques:

a. Decision tables: Business decisions use a particular set of input values to decide on a specific outcome, by using a detailed set of business rules to select one from the available results.

A decision table is a condensed, tabular representation of a set of these rules. Each row represents a rule and each column represents one of the conditions of that rule.

When all the conditions in a specific rule are true for a set of input data, the action described for that rule is selected.

b. Decision trees: Decision trees are also used to represent a set of business rules.

The branches on a decision tree leaf node are a single rule and a decision tree picks one of the available outcomes based on the particular values passed to it by the data elements.

c. Decision requirements diagrams: A decision requirements diagram is a pictorial diagram of the knowledge and decision making steps involved in making complicated business decision.

Decision requirement diagrams have the following components:

  • Decisions: these are represented by rectangles. Each decision takes a set of inputs and picks from a defined set of possible outputs by applying business rules and other decision logic.
  • Input data: these are represented by ovals, they represent data that must be inputted into a decision on the diagram.
  • Business knowledge models: these are represented by a rectangle with the corners cut off, and they represent sets of business rules, decision tables, decision trees, and predictive analytic models that describe how a decision is made.
  • Knowledge sources: these are represented by a document, which shows the source of the information. The knowledge could have been derived from documents or people.

All these elements are linked together into a network which shows how complex decisions are broken down making simpler building blocks.

When should you use a Decision Model ?

Decision models have both their strengths and limitations, which include the following:


  • Decision models are easy to use and explain to the stakeholders.
  • They are a useful tool in impact analysis.
  • They have multiple points of views which can be added to the diagrams.
  • The can help break down complex decisions into simpler ones.
  • They can be used for grouping business rules and enabling them for reuse.
  • The models work for both simple decision making process like manual decisions or complex decision making like rules-based automation.


  • You would need to use a second diagram style when modelling business processes that contain decisions, thus making them more complex.
  • Only those rules required by known decisions are shown and this may lead to misconceptions on the number of business rules that are needed. .
  • They may cause the stakeholders to believe that their decision models have been standardized.
  • They consider the enterprise as a whole and thus increase the number of stakeholder involved in its approval.
  • The business terminology must be clearly described to avoid issues related to the automated decisions.