A decision making model is a system that consists of axioms in which different actions can be executed to solve a given problem or to come up with a given conclusion to a situation. A decision model consists of a set of explicit and clearly defined rules that guide an individual in the collection, assessment and to process given information in order to be able to make a concrete decision to a given situation.

Evans R. James, in his work on statistics, data analysis and decision modeling outlines three types of inputs that are common to decision models, irrespective of the decision model that one decides to adopt. These inputs include; formulation, evaluation and appraisal. Formulation of actions to be adopted in every decision model helps in the development of a formal model of the given decision. This is the very first step in every decision making process. After the actions to be undertaken are formulated, the other input that comes into play is evaluation. This is after the actions are implemented. Evaluation is an important input as it helps to produce a formal recommendation. The recommendations are based on the objectives of the decision model adopted, the achieved or actual outcomes and the intended outcome of decision making. Evaluation input in decision models is vital as one is able to determine where to take some corrective measures to achieve the intended outcome.

The other input that is common to decision models is appraisal input. In every decision model, appraisal is of great help as it helps one to develop insight into the decision and determine a clear course of action. In appraising, one follows a clearly defined set of rules to assess and evaluate the information that is available to determine whether it is relevant to the problem in question and whether it the most appropriate model to use in decision making.

In conclusion, every decision model that is adopted is of help in decision model so long as relevant inputs necessary for decision making in each decision model are adopted.