When working in Dynamics 365 Finance and Operations (F&O), it quickly becomes clear that a poorly structured model setup can lead to major problems later on. Many upgrade difficulties, deployment failures, or suddenly missing customizations can often be traced back to an incorrect or weak foundation.
In D365 F&O, a model is not just a container for objects—it functions as the organizational backbone of your entire solution. It dictates how extensions are managed, packaged, and sustained across version upgrades and deployments. Getting this initial setup right is key to ensuring clean, maintainable customizations while avoiding the pitfalls of accumulating technical debt.
Here’s a step-by-step guide to building a new model from scratch—done smartly and with proven strategies to save you headaches later.
What a Model Truly Represents
In Dynamics 365 Finance & Operations, a model serves as a logical container that holds all your development artifacts—tables, classes, forms, data entities, and more.
While a Visual Studio project structures your code specifically for local development, a model plays a broader role by organizing it for lifecycle management. This includes versioning, deployment, and maintaining separation from Microsoft's core objects.
Essentially, a model acts as your personal sandbox within the Dynamics 365 ecosystem. You design and test your solutions within it, and when you're ready to deploy, you transfer only the elements you own—no extras, no omissions.
Why Creating a Model Should Always Be Your First Step
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Many developers dive straight into adding objects, thinking they'll "sort out the structure later." This approach often leads to serious upgrade headaches. Here's why starting with a well-designed model is essential:
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Organized Structure – Ensures your tables, classes, and forms are systematically grouped and easy to navigate.
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Upgrade Resilience – Protects your code from Microsoft's layers, simplifying updates and reducing risks.
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Efficient Version Tracking – Integrates seamlessly with source control, allowing you to monitor and track all changes effectively.
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Hassle-Free Deployment – Package your solution once and deploy it effortlessly across various environments.
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Enhanced Reusability – Apply the same model across different projects or environments with minimal tweaks.
Before starting, confirm that you have the following prerequisites:
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- Visual Studio with Dynamics 365 Developer Tools properly installed
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- Access to a valid Dynamics 365 Finance & Operations development environment
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- Administrative privileges to create models and packages
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- A well-defined naming and prefix convention specific to your organization
Step-by-Step: How to Create a New Model
1. Open Visual Studio as Administrator
Always launch Visual Studio with administrator privileges to avoid any permission-related issues when accessing system folders or generating packages.
2. Access Model Management
Navigate through the menu and select Dynamics 365 → Model Management → Create model. This will initiate the Model Creation Wizard.
3. Provide Model Details
Fill out the required fields with care:
Model Name: Use a descriptive name, such as RetailAnalyticsExtension.
Description: Include a brief explanation, like Retail performance customization for Power BI integration.
Publisher: Specify your organization name or prefix, e.g., RAX.
Layer: Always select the CUS (Customer) layer when creating customizations for a particular project or company.
Pro Tip: The publisher prefix you decide on will appear in various elements like classes, tables, and fields. Make sure it’s concise and meaningful.
4. Select a Package
Decide where your model will reside:
- Use Create new package if you’re building an independent customization.
- Select Use existing package if extending an existing area (e.g., ApplicationSuite).
Keeping custom models in a separate package is typically the best approach to prevent dependency conflicts during builds or deployments.
5. Review and Finalize
Before completing the process, thoroughly check:
- The prefix is correct and appropriate.
- The proper layer (CUS) is selected.
- You’ve chosen the right package option.
Once everything looks good, click Finish. Visual Studio will generate:
- A model descriptor file (Descriptor.xml).
- A metadata directory within your chosen package.
Now you have a dedicated workspace for streamlined development—your custom model is ready, cleanly structured, and isolated from other components.
Best Practices for Building Models Like an Expert
Here’s what seasoned D365 developers discover—typically after some trial and error:
1. Keep Names Clear and Consistent
Steer clear of cryptic naming conventions. A name like HRBenefitsExt is far more intuitive than something like Mod001. Clear names make debugging or merging significantly easier down the road.
2. Avoid Modifying Standard Code
Never alter Microsoft’s base tables, classes, or forms directly. Instead, rely on extensions, event handlers, and the chain of command. This ensures your solution remains upgrade-safe—a key principle for sustainable development.
3. Create Small, Purpose-Driven Models
Stick to the guideline of one model per business area for better organization and performance. Examples include:
- Payroll Enhancement
- WarehouseIntegration
- RetailPOSUpgrade
Smaller, focused models not only compile more quickly but are also easier to maintain in version control.
4. Adopt Source Control from the Start
Connect your model to a version control system like Git or Azure DevOps as soon as it’s created. Document every change, experiment with branches, and eliminate the risk of losing progress due to unexpected errors or oversights.
5. Document Consistently
Every model should include a clear description along with supporting documentation, such as an internal README or a wiki note. This makes it easier for future developers—or even yourself—to understand its purpose and functionality at a glance.
Common Pitfalls to Watch Out For
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Building a model in an incorrect layer (only use CUS for customer customizations)
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Combining unrelated business domains into a single large model
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Neglecting prefix naming (results in naming conflicts)
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Overlooking reference checks during model creation (can cause dependency errors down the line)
Conclusion
Developing a new model in Dynamics 365 Finance and Operations is more than just a basic configuration step; it lays the groundwork for robust, reliable, and sustainable development. When executed correctly, a model grants full control over customizations, keeps code well-organized, and ensures smooth deployments and updates.
By leveraging the appropriate layer (CUS), establishing clear naming conventions, structuring logic through extensions, and maintaining strict source control practices, you create a system that scales efficiently and adapts seamlessly to Microsoft updates.
Ultimately, think of model creation as a strategic move rather than a routine activity. A thoughtfully designed model minimizes complications, simplifies upgrades, and results in a trustworthy codebase. In the realm of D365 F&O, robust models pave the way for robust solutions.