Introduction to Bayesian networks and causal pathways

Many outcomes of interest across industries involve a sequence of events or choices to reach the outcome of interest. The arrival of packages depends on the safe arrival of packages at each relay point between shipping and arrival. Machinery failure can involve single points of failure (SPOFs) or cascades of failure, in which multiple parts of the machine fail before the machinery itself fails.

Consider the pathway to drug addiction. First, a person must be in a situation where drug use occurs—through friends, through family, or through a new social group. Then, a person must try an addictive substance. Then, they must like the substance enough to continue using the substance frequently enough to reach a point of physical or psychological dependence on the drug. Figure 10.1 shows this sequence of steps in a diagram format:

Figure 10.1 – A sequential progression of events leading to drug...