Learn about common workflows for designing 3D models in Inventor.
The various techniques and approaches that are available to model parts and create assemblies can affect performance. Your modeling approach determines the number of occurrences, complexity of geometry, constraint methods, and assembly creation. It is common to mix techniques to fit your products and design intent. You can use top down modeling to design and build a frame, and then use bottom up modeling to place and constrain components from a library.
Bottom Up is a traditional way to build assemblies. You first define the individual parts. Then you put them into subassemblies using assembly constraints. The subassemblies are then placed into higher level assemblies up to the top level assembly. You work your way from the bottom up. This assembly method results in assemblies with numerous relationships between parts and assemblies.
Top Down is a method where you start by defining the result, and build in all of the known design criteria. The result becomes the base for underlying subassemblies and parts. You have a single conceptual file containing the overall information of the design with a single place for incorporating design changes. This method can provide faster updates, more available resources for handling larger data sets, and an easier way to work in a collaborative environment. In general, it is a better way to do design work.