Starting Simple: Defining Events and Functions Effectively

Every business process begins with a trigger — a moment something changes. In EPC modeling, that moment is an event. Getting events and functions right from the start prevents confusion, misalignment, and wasted effort later. A poorly defined event creates ambiguity; a vague function hides responsibility. This chapter is not about complex systems — it’s about grounding your model in reality.

Over two decades of modeling enterprise systems has taught me: clarity isn’t about complexity. It’s about precision. The goal isn’t to capture every detail upfront — it’s to build a foundation that anyone can follow. Whether you’re modeling an order entry flow or an HR onboarding sequence, the logic remains the same.

This guide walks you through identifying real-world events and translating business actions into precise EPC functions. You’ll learn how to avoid common pitfalls, how to apply naming rules that stick, and how to build a simple EPC process that tells a clear story.

What Are EPC Events? The Heart of Process Triggering

An event in an EPC is a moment when a business situation changes. It’s not a task — it’s a state shift. Think: “An order was received.” That’s an event. Not “Receive order,” which is a function.

Events are always **state changes** — a confirmation, a rejection, a deadline passed. They mark the start or end of a process, or a point where a decision must be made.

Here’s how to identify a true EPC event:

• Ask: “Is this an occurrence that can be confirmed as happened?”
• Use past tense: “Payment received,” “Invoice approved,” “Customer registered.”
• Ensure it’s observable and measurable — not subjective.

Common examples of EPC events:

• Customer places order
• Payment received
• Invoice generated
• Employee onboarding completed
• Deadline expired

When you’re unsure, ask: “Would this trigger a next step?” If yes, it’s likely an event.

Common Mistakes in Defining EPC Events

Even experienced modelers fall into traps. Watch out for:

• Using verbs as events: “Submit application” — this is a function. “Application submitted” is an event.
• Overloading events: “Order processed” — too vague. Better: “Order confirmed” or “Order shipped.”
• Missing triggers: Not capturing key events like “Customer canceled order” can break logic.

Remember: Events are what happens. They’re the milestones.

What Are EPC Functions? The Actions That Drive Change

Functions are the actions that transform one state into another. They’re the tasks that cause an event to happen.

Unlike events, functions are verbs in the infinitive form or passive voice. They’re not states — they’re activities.

Consider this simple flow:

Event: Customer places order

Function: Validate customer details

Event: Validation successful

Here, “Validate customer details” is a function — it’s the action that leads to a new state.

Key Rules for Writing EPC Functions

1. Start with a verb: “Process order,” “Send confirmation email,” “Approve invoice.”
2. Be specific: “Process order” is okay. “Process order within 24 hours” is better.
3. One action per function: Avoid “Review and approve” — split into “Review application” and “Approve application.”

Using precise language ensures that roles, systems, and responsibilities are clear — a must for later process ownership.

EPC Function Examples in Real Processes

Here are practical EPC function examples from real business scenarios:

• Generate invoice from order
• Check credit limit
• Assign task to regional team
• Update customer status to “Active”
• Send welcome email to new employee

Each of these is a distinct, actionable step — not a state. This distinction is critical.

Building a Simple EPC Process: Step-by-Step

Let’s walk through a simple EPC process: Customer order fulfillment.

Start with a single, clear goal: “Deliver order to customer.” Then, identify the key events and functions.

Step 1: Identify the Start Event

Begin with: Customer places order

Step 2: Add the First Function

Next: Validate customer details

Step 3: Identify the Resulting Event

Then: Validation successful

Step 4: Add the Next Function

Then: Check inventory availability

Step 5: Add the Next Event

Then: Inventory available

Step 6: Add Final Function and End Event

Then: Ship order

End: Order delivered

Now you have a simple EPC process flow that’s logical, readable, and grounded in business reality.

Logical Operators: What to Use and When

Every EPC model will eventually need decision points. This is where logical operators — AND, OR, and XOR — come in.

Use them to model:

• XOR: One and only one path must be taken (e.g., “Payment method selected: Credit Card OR PayPal”)
• AND: All paths must be completed (e.g., “Approve order AND notify warehouse”)
• OR: One or more paths may be taken (e.g., “Send email OR send SMS notification”)

Use AND gates to model parallel tasks. Use XOR to model mutual exclusivity. Use OR for optional paths.

Keep it simple. Too many logical branches create complexity. Aim for no more than 3–4 paths per decision point.

Best Practices for EPC Clarity

Even a simple EPC process must be readable by people outside the team.

Here’s a checklist to ensure your EPC modeling guide delivers clarity:

• Use consistent tense: Events in past tense, functions in present or infinitive.
• Label with clarity, not jargon: “Process invoice” > “Process invoice (PO-12345)”
• Group related elements: Cluster events and functions by business phase.
• Use Visual Paradigm’s auto-layout: Helps maintain clean, readable alignment.
• Review with a non-expert: If they can’t follow the flow, simplify.

Why This Matters: The Long-Term Impact of Clear Modeling

When you define EPC events and functions correctly, you’re not just drawing a diagram — you’re building a shared understanding. This model becomes the basis for automation, audit trails, and system integration.

I’ve seen teams spend weeks rewriting processes because a single event was mislabeled. The cost? Delayed projects, wrong system designs, and stakeholder frustration.

Take the time now to define events and functions with care. It’s the single best investment you can make in the quality of your EPC diagrams.

Frequently Asked Questions

What is the difference between an EPC event and a function?

An EPC event is a state change — it confirms something has happened (e.g., “Order received”). An EPC function is an action that causes a change (e.g., “Process order”). Events are milestones; functions are tasks.

How do I define EPC events for a process with no clear triggers?

Start by asking: “What would cause this process to begin?” Look for external signals — a customer action, a system alert, a calendar date. If no trigger exists, the process might not be a standalone event chain. Reassess its scope.

Can I use EPC function examples from other industries?

Yes — but tailor them to your context. “Send confirmation email” is a valid example in many fields. However, replace generic terms with your actual process (e.g., “Notify customer of shipment” in logistics).

What are some simple EPC process examples for beginners?

Try these: Customer order processing, Employee onboarding, Invoice approval workflow, Service request fulfillment. Each starts with a clear event and flows logically through functions to a final outcome.

How do I avoid overcomplicating a simple EPC process?

Focus on the core flow. Remove redundant functions. Merge similar steps. Use logical operators only where needed. A well-structured EPC should be understandable in under 30 seconds.

What tools can I use to model EPC diagrams effectively?

Visual Paradigm is excellent for beginners and professionals. It supports auto-layout, real-time validation, and export options. Use templates to start quickly and follow best practices built into the tool.