There should be a reason for any engineering activity. This applies well to any structural health monitoring (SHM) project. The ultimate reasons for SHM activities should be either reducing costs or increasing safety. The way to ascertain that the SHM activities for a particular project would ultimately achieve the cost reduction and/or increasing safety is through the decision making tool chest. We define the decision making tool chest as a collection of quantitative or semiquantitative analytical methods and techniques that help the professional in analyzing different aspects of the SHM project and making appropriate decisions that would help to reduce costs or increase safety. This relationship is shown in Figure 8.1. Note that the decision making tool chest can be utilized to design the SHM experiment. It can also be used to assess the results of the SHM experiment. The utilization of the decision making tool chest depends on the type of SHM project, as well as the ultimate goals of embarking on the SHM project to start with.