Critical Path Method involves creating a network diagram that determines the shortest, most efficient way to complete a particular project. The drawing include the activities, which are are depicted as nodes, and events, which signify the beginning and ending of the diagrammed activities. There are six steps involved in CPM: specifying the individual activities, determining the order in which those activities will take place, illustrating the process in a network diagram, estimating how long each activity will take to complete, identifying the critical path to determine the longest path through the network and updating the diagram as the project progresses, indicating any changes to activities and timelines.
Critical Decision Method provides a model for tasks that will take place in naturalistic environments characterized by tight windows of time, a high level of information and constantly changing conditions. In CDM, a nonroutine incident from the past is recalled, and a set series of questions about that incident is used to determine how to best assess the situation to make effective decisions. Interviews are conducted with experts in a particular subject, with cognitive probe questions used to determine how to best assess a nonroutine incident and the decision-making involved. The aim of CDM is to reveal the subtle cues that experts will pick up on but may be overlooked by less-experienced people when assessing a situation.
CPM has a number of advantages, such as the ability to provide a graphical depiction of the project. In addition, CPM can offer a realistic prediction of the time required to complete the project and an indication of which activities are crucial to maintaining the schedule and which activities are not. The key advantage of CDM, on the other hand, is that the experts who are interviewed have the opportunity to define the range of the problem, as well as define which problems are most challenging. CDM also gives the person being interviewed the opportunity to identify areas in which experience makes the most difference.
The biggest disadvantage with CPM is that a complex project will result in a complex diagram, with the potential for thousands of activities and events. One of the key disadvantages of CDM is that analyzing all the data can be time-consuming. In addition, the results of CDM interviews may be misleading when an experienced person has the capacity to perform at a far-higher level than others, which could result in underestimation of potential problems.