What is iLogic? Complete Guide to
Autodesk Inventor Automation

What is iLogic?

iLogic is Autodesk Inventor's built-in CAD automation tool. It allows mechanical engineers to write rules — small programs — that automatically control part dimensions, suppress or activate features, populate Bills of Materials, update iProperties, and generate drawings, all without manual intervention.

Unlike third-party plugins or external scripts, iLogic is fully integrated inside Inventor. There's nothing to install. Every licensed copy of Autodesk Inventor includes iLogic out of the box.

What Can iLogic Automate?

iLogic can automate almost any repetitive task inside Autodesk Inventor. Here are the most common use cases:

1. Parametric Design Automation

Drive part dimensions, sketch constraints, and assembly configurations automatically based on input parameters. Change one value — iLogic updates the entire model.

2. Feature Control

Automatically suppress or activate Inventor features based on product configuration. For example: include lifting lugs only when load rating exceeds 5 tonnes.

3. iProperties Auto-Fill

Automatically populate Part Number, Description, Revision, Material, and custom properties across every part in an assembly. No more manual title block filling.

4. BOM Generation

Read component data from assemblies and auto-generate Bills of Materials with part numbers, quantities, and materials — all pulled from iProperties.

5. Drawing Automation

Automatically create drawing views, add dimensions, populate title blocks, and export to PDF — triggered by a single iLogic rule.

6. Excel Integration

Read product data from Excel spreadsheets and drive Inventor models directly from a data table. Ideal for product configurators and variant management.

How Does iLogic Work?

iLogic rules are written in a simplified VBA-like syntax. You don't need to be a programmer — if you can write an engineering specification ("if X then Y"), you can write an iLogic rule.

Here's a simple example of an iLogic rule:

This rule runs instantly whenever the LoadRating parameter changes — updating three dimensions in one shot.

iLogic vs Macros vs Add-ins

Engineers often confuse iLogic with Inventor macros or VBA add-ins. Here's the key difference:

• iLogic — built into Inventor, designed for engineers, event-driven, no installation needed
• VBA Macros — lower level, requires more programming knowledge, no native UI
• Add-ins (.dll) — most powerful but requires full .NET programming, compiled code

For 90% of CAD automation tasks, iLogic is the right tool. It's the fastest to learn and the most practical for day-to-day engineering work.

Who Should Learn iLogic?

iLogic training is most valuable for:

• Mechanical engineers using Autodesk Inventor daily
• CAD managers wanting to standardise design workflows
• Engineers building product configurators
• Design teams dealing with high-variant, repetitive products
• Anyone who spends more than 2 hours per week on repetitive CAD tasks

How Long Does It Take to Learn iLogic?

With structured iLogic training, most engineers can write working automation rules within their first 2–3 sessions. A complete iLogic training program covering all major features — parameters, feature control, iProperties, BOM automation, drawing output, and Excel integration — takes approximately 50 hours of live instruction.

At CAD Automator, our iLogic training program is structured across 19 modules and ~50 hours of live sessions, taking engineers from zero to confident automation in one complete programme.

Getting Started with iLogic

To start using iLogic in Autodesk Inventor:

1. Open Inventor → go to the Manage tab
2. Click iLogic → Add Rule
3. Name your rule and start writing in the editor
4. Click Run to execute the rule

The iLogic editor includes auto-complete for Inventor parameters and a browser panel showing all rules in your document. It's designed to be accessible even for engineers with no prior coding experience.