1. A method of managing concurrent design of computer-aided design (CAD) models, comprising: providing, to a processor of a computing device, a plurality of different CAD applications including (a) a modeling application configured to edit geometric features of the CAD models, (b) an engineering analysis application configured to perform engineering analyses on the CAD models, and (c) an assembly application configured to modify how different CAD models, each corresponding to a respective distinct physical object, are assembled together, each of the plurality of different CAD applications having an active state and an inactive state; executing, using the processor, a first CAD application selected from the plurality of different CAD applications such that the first CAD application is in an active state while, concurrently, a second CAD application of the plurality of CAD applications is in an inactive state, wherein the first application is the modeling application or the assembly application; storing, by the first CAD application executed by a processor of the computing device, a starting state of a CAD model; modifying the CAD model via the first CAD application executed by the processor in response to commands from a user; creating, by the first CAD application and responsive to the modification, a first one or more change instructions representative of the modification to the geometric features of the CAD model; sending the first one or more change instructions of the geometric features to the second CAD application, the one or more change instructions being sent when the second CAD application is in the inactive state, wherein the second application is the engineering analysis application; and responsive to a selection of the second CAD application by the user, automatically changing, by the processor, (a) the first CAD application from the active state to the inactive state and (b) the second CAD application from the inactive state to the active state, wherein responsive to the change of the second CAD application from the inactive state to the active state, automatically loading, by the processor, the stored starting state of the CAD model and automatically executing the one or more change instructions of the geometric features, by the processor executing the second CAD application, wherein the execution of the one or more change instructions produces a modification to the engineering analyses of the CAD model for the engineering analysis application.