A main challenge in maintenance analysis is to assess the effect of maintenance on the overall maintenance performance measures, like e.g. track availability, resistance against derailment, low noise etc.
To help establishing such cause and effect models influence diagrams have shown efficient. An influence diagram shows the relation between decisions (e.g. maintenance actions), random quantities (e.g. number of delays), and values (e.g. cost of delays). The diagram comprises nodes and arrows.
The diagram is a good communication tool between the analyst, the maintenance people, and economists. This has been demonstrated in several projects and courses in RAMS analysis. The diagram is used as a communication tool to identify the relevant "nodes" and "arrows" in terms of what to focus on (nodes in terms of decisions, random quantities, and values, and arrows in terms of what influences should be considered). The diagram is a basis for setting up the mathematical model that will be used in the final optimisation of maintenance program.
An example of an influence diagram could be found here. A detailed analysis of maintenance options utilizing influence diagrams could be found here.
Influence diagrams have proven efficient in the process of establishing life cycle cost models (LCC).