Designers want the ability to edit parts within the context of an assembly (top-down design) to ensure fit and function by defining relationships between components.Onshape believes that traditional approaches to top-down design have demoed well, but have not largely been successful when used in real-world design scenarios.
Due to complex relationships being stored in multiple files, Traditional CAD users often experience both unpredicted geometry changes and feature corruption when using in-context relationships. Users have no control over how and when these complex relationships update. Sometimes the relationship is recalculated when a part is rebuilt; sometimes when the assembly is updated.
Many companies have banned the use of in-context relationships because of their unpredictability. In fact, some CAD tools have a user-defined setting that will prevent their creation.
Onshape claims to have solved these problems. With its new capabilities: Models are said to update in a predictable, controlled manner; motion does not affect in-context relationships; multiple assembly contexts can be used to edit a single or multiple parts; and the assembly context (the state of the assembly) can be updated if needed.
Combined with the power of its Part Studios (multiple-part design environment) and full-cloud CAD's ability to restore to any point in time, Onshape says its update is in-context design at its best, especially when design engineers know their design intent upfront.