This article highlights how to make integrating major subassemblies, e.g. suspension, into the full assembly an easy and relatively error-free process.
Why They are so Prone to Errors
Large subassemblies which contain many parts and are often flexible also usually require many mates in the full assembly to be fully defined. Unfortunately, the flexible property of many of these subassemblies means that for top-level mates to be solved correctly, SolidWorks must also simultaneously solve mates within the subassembly at the top-level. This is a very time consuming process, and also mathematically quite complicated, hence the propensity for mate errors.
The Theory on How to Get Around This
The best solution to this problem is to design subassemblies in a way such that they require only a single Coincident mate in order to be fully defined, setting the coordinate systems of the subassembly and full assembly as identical. This is a very simple mate for SolidWorks to solve and means that all mates within the subassembly do not have to solved simultaneously with top level mates.
Implementing Identical Coordinate Systems
In order to make this possible, there needs to be a standardized coordinate system which all subassemblies may use to position components properly. This is done by using the frame coordinate system as the full assembly coordinate system. The frame can be added to major subassemblies and mated in place as mentioned in the previous section. The frame, now, may be used to mate all of a major subassembly's components into the correct position, with respect to the full assembly.