Explanation of change (EoC) study: Considerations and implementation challenges

This paper discusses the implementation of considerations resulting from a study investigating the cost change experienced by historical NASA science missions. The study investigated historical milestone and monthly status report documentation followed by interviews with key project personnel. The reasons for cost change were binned as being external to NASA, external to the project and internal to the project relative to the project´s planning and execution. Based on the results of the binning process and the synthesis of project meetings and interviews, nine considerations were made with the objective to decrease the potential for cost change in future missions. Although no one “magic bullet” consideration was discovered, the considerations taken as a whole should help reduce cost and schedule change in future NASA missions.