Just as you can combine features into parts, you can also combine parts into assemblies. Creo Parametric enables you to place component parts and subassemblies together to form assemblies. You can modify, analyze, or reorient the resulting assemblies. You can combine non-native parts to create a Multi-CAD assembly.

Creo Parametric provides basic assembly tools, and various Creo Parametric modules give you additional functionality for assembly operations.

Assembly supports the design and management of large and complex assemblies through the use of powerful tools such as simplified representations, interchange assemblies, and the use of Top Down design procedures.

Simplified representations are variations of a model you can use to change the view of a particular design, enabling you to control which members of an assembly are brought into session and displayed. This lets you tailor your work environment to include only the information of current interest to you. You can, for example, temporarily remove a complicated subassembly from memory that is unrelated to the portion of the assembly on which you need to work. You can also substitute a complicated subassembly or part with a simpler part or envelope.

Using advanced performance tools, you can speed up the retrieval process and general work performance of large assemblies using simplified representations.

Simplified representations also allow you to show a component in a symbolic state. This means that no geometry is shown for a component. Instead, a symbol represents placement of the component. Mass properties can be calculated using the placement point of the components and actual mass properties of the part. You can also create a user defined 3D symbol to represent the symbolic part.

External representations can be created without modifying the master assembly. External simplified representations are created in separate specialized assembly files.

An interchange assembly is a special kind of assembly that you can create and then use in a design assembly. An interchange assembly consists of models that are related either by function or representation. You can create both functional interchanges (to replace functionally equivalent components) and simplify interchanges (to substitute components in a simplified representation) in the same interchange assembly. Interchange assemblies, like family tables and notebooks, provide a powerful method of automatic replacement.

The skeleton model of the assembly is the framework of the assembly. A skeleton model is a specialized component of an assembly that defines skeletal, space claim, interface, and other physical properties of an assembly design that you can use to define geometry of components. In addition, you can use skeleton models to perform motion analysis on an assembly by creating placement references to the skeleton model and then modifying the skeleton dimensions to imitate motion.

Skeleton models can be used to capture in a central location design criteria defined in the subassembly or delivered from a higher-level assembly. Using skeleton models in more than one assembly allows you to distribute design criteria associatively throughout the product structure. When design criteria change, updating is propagated to affected components. Skeleton models provide a clearly understood hierarchy of driving design criteria, they provide an organized display, and they allow improved performance. Skeleton models are the recommended mechanism for controlling top-level design iterations, and you can use them to facilitate task distribution.

Skeletons are represented by a unique icon in the Model Tree because their functional characteristics are significantly different from those of other components. Skeleton models can be filtered out the BOM and drawing views and can be specially handled during the creation and manipulation of simplified representations and Shrinkwrap features. Skeleton models are placed before all other components with solid geometry in the model tree. Reference scope control settings can be used to restrict making assembly placement references to skeleton models only.

Skeleton models, like regular components, can be replaced by both family table instances and other skeleton models. You can copy a part model component into a new skeleton model, as long as the part model satisfies the skeleton model criteria. You can generate a native skeleton model, based on a native part model, and have it replace the part model in an assembly, with all references remapped to the new skeleton model. This effectively allows a part to be designated as a native skeleton model, through the use of a new model file.

Skeleton models can maintain their own family tables. This enhancement allows assemblies to maintain different skeleton instances across a family table.

Although skeletons can be created only within an assembly, they can be retrieved, operated upon, and saved as ordinary parts.

The optional NOTEBOOK module supports top-down assembly design with tools that enable you to create hierarchically-linked assembly notebooks.

Assembly Process Planning enables you to create a drawing that illustrates the assembly process of the assembly. Assembly steps are defined using the actual assembly. Each process step can be further described with specific exploded views, simplified representations, parameters and notes assigned to each process step.