Collaboration Models: Managing the Crew

How should your agents talk to each other? Should Agent A always finish before Agent B starts? Or should there be a "Manager" who decides the order? In CrewAI, this is defined by the Process.

1. The Sequential Process (Standard)

The tasks are executed one after the other.

• Pattern: A -> B -> C.
• Best for: Linear workflows like research and writing.
• Advantage: Very easy to debug. You know exactly where the project failed.

---

2. The Hierarchical Process (Advanced)

In this model, you don't define the order. You define a Manager Agent.

• The Manager receives the goal.
• The Manager reviews the team's roles.
• The Manager assigns tasks dynamically.
• The Manager reviews the output and decides if it needs to be sent back for a rewrite.

graph TD
    User[Project Goal] --> Manager[Manager Agent]
    Manager <--> W1[Worker: Researcher]
    Manager <--> W2[Worker: Writer]
    Manager <--> W3[Worker: Designer]
    Manager --> Final[Final Result]

Why use a Hierarchical model?

It handles Cycles and Validation automatically. The Manager acts as the "Validator" we studied in Module 3.

---

3. Consensual Collaboration

While not a native "Process" keyword, you can build consensual patterns where Agent A and Agent B must both "Approve" an output before it moves to Task 3.

• Example: A Technical review + A Financial review must both pass before a project is greenlit.

---

4. Code Example: Defining the Process

from crewai import Crew, Process

# 1. Sequential (The Default)
crew = Crew(
    agents=[researcher, writer],
    tasks=[task1, task2],
    process=Process.sequential
)

# 2. Hierarchical (Requires a Manager LLM)
crew = Crew(
    agents=[researcher, writer],
    tasks=[task1, task2],
    process=Process.hierarchical,
    manager_llm=manager_llm # The brain that organizes the work
)

---

5. Summary Matrix: Which to Choose?

Task Complexity	Recommendation	Why?
Straightforward	Sequential	Fast, low cost, easy to track.
Ambiguous	Hierarchical	The Manager handles the exploration.
High Quality	Hierarchical	Built-in review and revision cycles.

---

Key Takeaways

• Sequential is the "Conveyor Belt" of task management.
• Hierarchical is the "Office" of task management.
• The Manager Agent acts as a dynamic router and quality checker.
• Choosing the right model depends on the Predictability of your workflow.