Final answer:
The Critical Path Method (CPM) was originally used for constructing nuclear submarines and is now used in project planning and production processes, such as those used in the design of the Boeing 777, to manage critical paths and schedules effectively.
Step-by-step explanation:
The tool originally used for constructing nuclear submarines that is now used to plan projects and determine critical paths during production is known as the Critical Path Method (CPM). In the context of engineering design processes, such as the creation of the Boeing 777, CPM is instrumental in scheduling and managing complex tasks. The method assists in optimizing schedules by identifying the longest sequence of activities required to complete a project, known as the critical path, which determines project duration and shows where delays can occur without impacting the final deadline.
For instance, in the 777 design process, sophisticated Computer-Aided Design and Drafting (CADD) systems, including Computer Graphics Aided Three-D Interface Application (CATIA) and Electronic Pre-Assembly In the Computer (EPIC), illustrated the close integration of design tools with project management techniques to ensure that all components would fit together seamlessly and the final product could be delivered on time. These systems also help in creating mathematical models that estimate costs for various approaches, an essential part of the engineering design process. This can lead to more informed decision-making in regards to the budget for product development.