Decision models

Decision models are used to determine which activities are recommended for the assets in a needs analysis run. A decision model is a tree-like structure consisting of two types of nodes:

• A decision node uses a formula to apply a true/false test to each asset in the analysis run. The result of this test determines the path that the asset will take through the decision tree.
• A result node is displayed at the end of each series of decision nodes. The result node specifies one or more activities to be performed on the asset. It also includes formulas that calculate the cost and benefit of the activities, and the target year in which they should be performed.

The root node and each decision node typically have two or more decision nodes as children. During an analysis run, each asset begins at the first child of the root node. If the formula for this node returns True, then the asset moves to its first child. If the formula returns False, then the asset moves to the next child of the root node. The process is repeated until the asset reaches a result node.

For example, a city creates a decision model to analyze the pavement conditions of its street segments and recommend maintenance activities. The decision model first checks the surface type of each street segment, such as asphalt or concrete. It then checks the type of street segment, such as arterial or local. Finally, the decision model checks an inspection index called the overall condition index (OCI) and recommends an activity based on the OCI. For example, a street segment with a high OCI value, indicating that it is in good condition, might only require a crack seal. A street segment with a low OCI would require reconstruction.

When you initiate a needs analysis you can specify a primary decision model and a secondary decision model. The primary decision model selects the first maintenance or rehabilitation activity that is required for each asset in the analysis. The analysis for the primary model is based on the most recent asset information and the most recently updated indexes.

The secondary decision model can be used to run a second analysis based on the results from the primary decision model. For the secondary analysis, Infor Public Sector recalculates the asset indexes based on the affected index formulas for the activity selected by the primary decision model. The assets in the analysis run are then put through the secondary decision model, which recommends a second set of activities.