Optimize assembly development

Category: Performance, Maintainability, Design

Impact potential: Low


When developing custom assemblies, there are a couple of considerations to take in:

  1. Assemblies with a large number of custom workflow activities can take a long time to upload when being registered.
  2. Multiple different custom assemblies
    • Increased maintainability complexity
    • Potential increase plug-in execution length
  3. Sandbox assembly size constraint is 16 MB in Microsoft Dataverse.


Limit the number of Custom Workflow Activities in a Single assembly

When an assembly that contains custom workflow activities is uploaded during plug-in registration, additional checks are required for custom workflow activities.

While an assembly with hundreds of ordinary plug-in types may be uploaded very quickly, an assembly with more than 100 custom workflow activities may take several minutes or even time out when being registered or updated. We recommend including no more than 50 custom workflow activities in a single assembly.

Consolidate Plug-ins or Custom Workflow Activities into a Single Assembly

Plug-ins and custom workflow activities developed for a Dataverse solution should exist with others in a single Visual Studio project. Consider merging separate plug-ins/custom workflow activities into a single Visual Studio project/assembly unless the plug-ins fall into the following exceptions:

  1. A plug-in/custom workflow activity needs to be selectively deployed to one environment but not to others.
  2. The physical assembly size is near or greater than 16 MB for a Dataverse instance.
  3. There will be more than 50 custom workflow activities in the assembly, as mentioned in Limit the number of Custom Workflow Activities in a Single assembly

Move Plug-ins/Custom Workflow Activities into Multiple Assemblies

Power Apps and Dynamics 365 (online) has an assembly size constraint of 16 MB which cannot be changed. If your assembly size is nearing 16 MB, consider moving plug-in/custom workflow activities into multiple assemblies.

Problematic patterns

Assemblies take a long time to upload when being registered

When a custom workflow activity type plug-in is uploaded while being registered, each type requires additional validation checking. When an assembly contains more than a hundred custom workflow activity type plug-ins, it could require several minutes to complete the checks and is at risk of timing out.

Multiple assemblies

Having multiple assemblies has a couple of areas that can be impacted:

  1. Performance - each assembly has a lifecycle that is managed by Dataverse. This includes loading, caching, and unloading the assemblies. Having more than one assembly causes more work to be done on the server, loading and caching an assembly, and could affect the overall plug-in/custom workflow activity execution length.

  2. Maintainability - having more than one plug-in/custom workflow activity Visual Studio project leads to more complex application lifecycle management (ALM). It increases the risk and the amount of time when updating/patching the appropriate project for a specific plug-in/custom workflow activity, packaging the plug-ins/custom workflow activities within a solution, and managing plug-ins/custom workflow activities within a deployment.

Assembly larger than 16 MB

You will not be able to register a custom assembly within Dataverse that is larger than 16 MB.

Additional information

Quite often, developers create a new Visual Studio project for each plug-in/custom workflow activity. In turn, this causes a separate assembly to be generated for each plug-in/custom workflow activity.

See also

Event Framework
Use plug-ins to extend business processes