Computer-aided design (CAD) concurrent design management includes a common data model, comprising chapters of different information items to describe various aspects of the CAD model, and lightweight change instructions representative of modifications made by a user to a chapter of the CAD model. By utilizing a common data model and difference-based change instructions, a plurality of users may concurrently collaborate on the design of a CAD model, or a single user may utilize a plurality of applications of a CAD suite efficiently and with an enhanced user experience. Furthermore, the system may manage undo stacks across a plurality of applications concurrently operating on the same shared CAD model, such that the user experiences seamless operation of the plurality of applications.