Setting Up a CRC Session: People, Cards, and Objectives

When a team stops arguing about class boundaries and starts sketching responsibilities on paper, you know they’re no longer just learning CRC—they’re using it. That moment of clarity, when abstract design becomes tangible and shared, is what I’ve seen mark the difference between theory and practice.

Setting up a CRC card session isn’t about tools or templates. It’s about creating the right conditions: a focused group, clear goals, and roles that empower collaboration. I’ve run dozens of these sessions across startups and enterprise teams. The most effective ones don’t rely on perfect facilitation—they thrive on shared purpose.

This chapter gives you the exact steps to run a productive CRC card workshop, whether you’re leading a classroom, a sprint planning meeting, or just starting your journey in object-oriented design.

Preparing for Success: The Pre-Workshop Checklist

Good design starts with good preparation. Skipping this step leads to confusion, wasted time, and half-formed models.

Define the Objective Clearly

Before inviting anyone, answer: *What problem are we solving with this session?*

Examples:

• “Identify core classes in the user authentication system.”
• “Break down the checkout process into manageable responsibilities.”
• “Explore how billing and inventory interact in the order system.”

A clear objective keeps the discussion focused and prevents aimless card writing.

Recruit the Right People

Invite 4–6 participants. More than that, and the session becomes chaotic. Fewer than 3, and you lose diverse perspectives.

Pick a mix of roles to ensure balanced thinking:

• One developer with domain knowledge
• One business analyst or product owner
• One junior developer or designer
• One person familiar with software design principles (even if new)

This diversity prevents groupthink and surfaces edge cases early.

Gather Materials

You don’t need digital tools to start. Physical cards are faster for brainstorming.

Prepare:

• At least 50 index cards (3×5 inches)
• Markers (black, blue, red)
• Sticky notes (optional, for grouping)
• A whiteboard or large table

If using digital tools like Visual Paradigm, ensure access and familiarity. But start physical—speed and tangibility build momentum.

Assigning Roles for Effective Collaboration

When roles are clear, responsibilities become visible. A team that knows who does what moves faster and with less friction.

Facilitator: The Conversation Guide

The facilitator keeps the session on track. They don’t lead the design—they guide the process.

Key responsibilities:

• Introduces the objective
• Enforces timeboxes
• Encourages participation from quieter members
• Prevents side discussions
• Rephrases unclear ideas

Important: The facilitator should not be the sole designer. Their job is to create space for thinking, not to drive it.

Scribe: The Memory Keeper

The scribe writes down every idea—no editing, no summarizing.

They ensure that:

• All class names are captured
• All responsibilities are listed verbatim
• All collaborations are recorded

After the session, the scribe helps compile the output. Their work becomes the foundation for diagrams or documentation.

Optional: Timekeeper & Deviator

• Timekeeper: Keeps the session within time limits (e.g., 15 minutes per phase).
• Deviator: Challenges assumptions. Asks, “What if this responsibility belongs to another class?”

These roles deepen thinking without overburdening the team.

Step-by-Step Guide to a Productive CRC Card Workshop

Follow this sequence to turn a group of individuals into a collaborative design team.

Step 1: Set the Stage (5 minutes)

Begin by sharing the objective. Explain why this matters: “Today, we’ll design the core structure of the order system so we can plan the next sprint.”

Set ground rules:

• No criticism of ideas during brainstorming
• One idea per card
• Use simple, action-oriented language for responsibilities

Step 2: Brainstorm Classes (10–15 minutes)

Have participants write down class names on cards. Encourage bold ideas—“Order,” “PaymentProcessor,” “CustomerService.”

Pro tip: Use sticky notes to cluster related classes. This helps spot missing or overlapping concepts early.

Step 3: Assign Responsibilities (10 minutes)

For each class, ask: “What does this class *do*?”

Write one responsibility per line. Use verbs:

• “Calculate total cost”
• “Validate payment information”
• “Send confirmation email”

Encourage specificity. Avoid vague phrases like “handle data” or “manage orders.”

Step 4: Define Collaborations (10 minutes)

Ask: “Which classes does this one *work with*?”

Draw arrows between cards. Label them with the interaction:

• “Calls”
• “Depends on”
• “Sends to”

This reveals dependencies and potential coupling.

Step 5: Review and Refine (10 minutes)

Step back. Ask:

• Are responsibilities clear and distinct?
• Are any classes doing too much?
• Are collaborations logical and minimal?

Reassign or split overloaded classes. Merge duplicates.

Common Pitfalls and How to Avoid Them

Even with solid steps, teams fall into predictable traps. Here’s how to spot and fix them.

Pitfall	Why It Happens	How to Fix
Too many classes	Over-modeling from the start	Ask: “Could this be a responsibility of another class?”
Vague responsibilities	Using abstract verbs like “manage” or “handle”	Rephrase using action verbs: “Process payment” instead of “Manage payment”
One person dominates	Lack of role clarity	Enforce round-robin sharing: each person speaks before repeating
Collaborations are unclear	Assuming “works with” means “uses” without specifying	Label interactions: “Calls,” “Depends on,” “Returns data to”

Why CRC Teamwork Works

When a team practices CRC teamwork, they’re not just designing software—they’re training their shared understanding. The real value isn’t in the final cards. It’s in the conversation they spark.

Each time someone says, “Wait, does the Order class really need to send emails?”—they’re already thinking about responsibility, cohesion, and decoupling.

Facilitating CRC design isn’t about being the smartest person in the room. It’s about being the calm center that helps others think clearly.

When you run a CRC card workshop right, you’re not just building a model. You’re building a shared language.

Frequently Asked Questions

How long should a CRC card session last?

For a small project or initial modeling, 45–60 minutes is ideal. For complex domains, break it into 20–30 minute sessions over multiple days.

Can I run a CRC workshop remotely?

Yes, but use digital tools like Visual Paradigm. Keep cards visible and collaborative. Enforce time limits and rotation to maintain engagement.

What if the team disagrees on a responsibility?

That’s expected. Don’t force consensus. Record both versions. Use a voting system or decide based on domain logic: “Which class is closest to the action?”

Do I need a facilitator every time?

Not always. For experienced teams, rotate the role. But for first-time sessions, assign a dedicated facilitator to build confidence and structure.

Should I use physical cards or digital tools?

Start physical. It’s faster and more intuitive. Switch to digital only when sharing, refining, or integrating with other models like UML class diagrams.

How do I know if the session was successful?

Success means: classes are clearly defined, responsibilities are specific and non-redundant, collaborations make sense, and the team voices shared understanding. If the group leaves with questions about roles or dependencies, the session needs refinement.