When to Use Plugins or Custom Workflows in Dynamics 365 CRM?

In Dynamics 365 CRM, automating business logic is a key part of delivering a smooth user experience. Two major tools used for this are Plugins and Custom Workflows. While they may seem similar at first glance, they serve different purposes and are suited for different scenarios. Let’s explore what a workflow is, how custom workflows work, how they differ from plugins, and when to use each.

✅ What is a Workflow in Dynamics 365 CRM?

A Workflow in Dynamics 365 CRM is an out-of-the-box tool used to automate business processes such as sending emails, updating fields, creating records, or triggering approval logic — all without writing code. Workflows can be triggered automatically (on create/update/delete), or manually (on-demand), and they run either in real-time or asynchronously in the background.

🔹 Key Characteristics:

• Can be configured using the visual Workflow Designer.
• Does not require developer skills.
• Supports real-time or background execution.
• Used for automating routine tasks like notifications or simple updates.

✅ What is a Custom Workflow in Dynamics 365 CRM?

A Custom Workflow is a .NET-based assembly that allows you to extend the built-in workflow functionality. It provides a way to implement complex business logic that cannot be achieved with standard workflow actions.

🔹 Example Use Case:

Imagine you want to calculate a discount based on customer type every time a quote is created. While out-of-the-box workflows have limited calculation capability, a Custom Workflow Activity can handle this complex logic.

➔ Plugin vs Custom Workflow: Key Differences

🛠️ When Should You Use Plugins or Workflows?

💪 How Do Plugins and Workflows Work? With Examples

1. Plugin Example

Scenario: Automatically set a “Contact Number” when a new contact is created.

public class SetContactNumberPlugin : IPlugin
{
    public void Execute(IServiceProvider serviceProvider)
    {
        var context = (IPluginExecutionContext)serviceProvider.GetService(typeof(IPluginExecutionContext));
        var serviceFactory = (IOrganizationServiceFactory)serviceProvider.GetService(typeof(IOrganizationServiceFactory));
        var service = serviceFactory.CreateOrganizationService(context.UserId);

        if (context.InputParameters.Contains("Target") && context.InputParameters["Target"] is Entity)
        {
            Entity contact = (Entity)context.InputParameters["Target"];
            if (contact.LogicalName == "contact")
            {
                contact["new_contactnumber"] = "CUST-" + Guid.NewGuid().ToString().Substring(0, 8);
            }
        }
    }
}

Register this on the Create message for the Contact entity (Pre-operation stage).

2. Custom Workflow Activity Example

Scenario: Calculate years of experience from a joining date.

public class CalculateExperience : CodeActivity
{
    [Input("Joining Date")]
    public InArgument<DateTime> JoiningDate { get; set; }

    [Output("Years of Experience")]
    public OutArgument<int> YearsOfExperience { get; set; }

    protected override void Execute(CodeActivityContext context)
    {
        DateTime joiningDate = JoiningDate.Get(context);
        int years = DateTime.Now.Year - joiningDate.Year;
        YearsOfExperience.Set(context, years);
    }
}

After deploying, this custom step can be used in the Workflow Designer to set field values dynamically.

🤔 Summary Table