4 FCM Diagram

An FCM model can be visually represented by an FCM diagram. FCM diagrams are made up of nodes and causal connections. Each node represents a concept with causal connections linking the concepts to represent the interdependencies in the diagram.

Causal Connections

Each connection links two concepts. The causal connections are defined by direction, polarity, and causal strength. The direction of the connection determines which concept exerts influence. The polarity indicates whether the relationship between these concepts is positive or negative i.e. directly or inversely proportional.

The causal strength of a connection determines the degree of influence one concept has over another, where a minimum value of 0 would indicate there is no influence between the concepts, and a maximum value would indicate that a concept has a maximal proportional influence over another concept.

Nodes

A node in an FCM diagram represents a concept with a value. Within MADE, the flow properties in the system are represented by nodes in an FCM diagram. In MADE, a flow property in nominal operation has a value of 0.0. When that value deviates above or below the nominal value, the flow property has entered a failed state.

Figure 3 ("FCM Diagram Representation of a MADE Model — each node represents an outflow property") shows a chain of nodes with causal strength (CS) labels, all CS = 10.0:

Continuous Amplitude (Input from MUX) ──CS=10.0──▶ Mech.–Rot. Angular Velocity (Pump Motor) ──CS=10.0──▶ Liquid Flow Rate (Fuel Pump)
Electrical Voltage (Input from MUX)   ──CS=10.0──▶ Mech.–Rot. Angular Velocity (Pump Motor)
Liquid Flow Rate (Input from MUX) ──CS=10.0──▶ Liquid Volume (Fuel Tank) ──CS=10.0──▶ Liquid Flow Rate (Fuel Line 3) ──CS=10.0──▶ Liquid Flow Rate (Fuel Filter) ──CS=10.0──▶ Liquid Flow Rate (Fuel Line 2) ──CS=10.0──▶ Liquid Flow Rate (Fuel Pump)

This diagram illustrates that each node = one outflow property of a MADE item, and causal connections carry a causal-strength (CS) weight — here uniformly 10.0 (i.e. maximum causal strength on the 1–10 scale used in the MADE UI, corresponding to 1.00 on the internal 0.10–1.00 scale used by the FCM engine — see the FCM Properties section for the scaling detail).