July 10, 2025

Implementing Model State in Parts and Assemblies within Autodesk Inventor

Gideon Bezuidenhout | Application Engineer

Model States are a powerful feature in Autodesk Inventor that allows you to create and manage multiple variations of a part or assembly within a single file. Whether you’re handling different manufacturing stages, design configurations, or simplified representations, Model states allow you to save configured variations of components, parts, and assemblies within a design. They serve various purposes, such as optimizing assembly performance, minimizing visual clutter in large assemblies, and facilitating specialized applications like manufacturing or FEA analysis

What Are Model States?
Model States let you define and store:

Dimensional variations, like different lengths or hole patterns
Suppressed or active features (e.g., fillets, holes)
Suppressed or replaced components in assemblies
Alternative materials or physical properties
Specific manufacturing stages, such as raw, machined, or finished conditions

📌 Think of it as a smart design table that lives inside your part or assembly file

Common Use Cases for Model States
✅ 1. Manufacturing Stages:
Show different steps such as casting, machining, and final finishing—all in one file.

✅ 2. Configurable Product Variants:
Model multiple sizes, features, or options for a product family without duplicating files.

✅ 3. Simplified Representations:
Create lightweight versions of assemblies for documentation, simulation, or sharing with stakeholders.

✅ 4. BOM Management:
Define unique Bill of Materials (BOM) entries for each model state to accurately represent variations.

✅ 5. Drawing Automation:
Connect drawing views directly to specific model states for precise, streamlined documentation.

Model States vs. iParts
Model States, introduced in Autodesk Inventor 2022, offer an updated alternative to iParts for managing multiple variations of a part. With this update, Model States and iParts are mutually exclusive, meaning you cannot use both features in the same part file.

Benefits of Using Model States
Simplified File Management: Store all part or assembly variations in a single file, reducing file sprawl.
Improved Performance: Easily switch between detailed and simplified representations to optimize large assemblies.
Flexible Documentation: Link different model states to specific drawing views or assemblies for clear, accurate documentation.
Design Efficiency: Quickly create, explore, and manage multiple design options without duplicating files.

Using Model States in Drawing Views
When creating drawing views in Autodesk Inventor, you can choose which Model State to display. This gives you flexibility to document different configurations, manufacturing stages, or simplified representations directly within your drawings. You can also update an existing parent view to switch to a different Model State as needed.

Understanding Assembly Model States

Assembly model states serve multiple purposes within an assembly. They can be used to create manufacturing stages, simplify the assembly display for design work, or configure components to represent different product variations. Model states are also valuable for improving retrieval times and performance when working with large assemblies. Additionally, they can act as a reference point for model simplification.

Model States vs. iAssemblies (Summary)
Model states were introduced in Inventor 2022 as a replacement for the previous Level of Detail functionality and as an alternative to iAssemblies. Model states and iAssemblies are mutually exclusive, with model states enabled by default in all new assemblies. If the assembly does not contain iAssemblies, model state functionality is enabled, and existing Level of Detail representations are converted to model states. If the assembly does contain iAssemblies, model states are not enabled, and existing Level of Detail representations are converted to Design View representations. Converting an iAssemblies table from a pre-2022 assembly to model states is a manual process. Users must either delete the iAssemblies table and recreate configurations using model states or use a spreadsheet to manage the conversion

Working with Substitute Model States

A Substitute Model State allows you to replace a complex component with a simplified version while retaining essential information such as material properties, center of gravity, and mass. Using substitute parts helps optimize performance by reducing the number of components loaded into memory and minimizing constraints and adaptive relationships that need recalculating. This approach enhances efficiency without compromising access to the BOM (Bill of Materials) data.

Parts Lists and Model States in Drawings
Parts lists and drawing tables must be associated with a view when created. If the view represents a model state, the parts list will reflect the changes made in that model state. For example, if components are suppressed in the model state, their quantities will be updated accordingly. If a component does not exist in the model state, it will still appear in the parts list with a quantity of 0, unless the “Suppress Components in BOM” option is enabled in the Bill of Materials dialogue box. When this option is enabled, all components with a quantity of 0 will be removed from the parts list.

Considerations When Working with Model States in Drawings

If design changes are made to a model state that is used in a drawing view, the drawing will update to reflect these changes when opened again. Any associated part lists or general tables will also be updated accordingly.
The model state assigned to a view can be switched by editing the view and selecting a different model state from the dropdown list.
Views can be modified to replace each reference model and its associated model state using the Replace Model Reference option on the Manage tab.
If a substitute component is used in the model state to represent an assembly, it will still be identified as a single item, ensuring an accurate BOM and parts list.

Model States provide a powerful way to manage different configurations of assemblies, optimize performance, and simplify complex designs. By using Model States, you can streamline workflows, improve retrieval times, and maintain accurate documentation in drawings and BOMs. Mastering these tools will enhance efficiency in large assembly management and design flexibility, ensuring a smoother engineering process.