Unit 03.02: Choosing on structure, not on ambition

The choice between processes should fall out of four questions about the work, not out of how sophisticated the design should look.

Four questions, one of which decides most cases

Do you know the order in advance? Does the order depend on a result? Can the routing rule be written down? Do tasks need different agents?

The code lists all four with what each implies.

QUESTIONS = [
    ("Do you know the task order in advance?", "sequential"),
    ("Does the order depend on a result?",     "hierarchical or a flow"),
    ("Can the routing rule be written down?",  "a flow -- do not pay a manager"),
    ("Do tasks need different agents?",        "either; this does not decide it"),
]

for question, implication in QUESTIONS:
    print(f"{question:42} -> {implication}")

print("""
The third row is the one that decides most real cases. If you can write the
routing rule down, a deterministic flow does it for free, correctly, every
time -- and a manager agent does it for the price of a model call, correctly
most of the time.

Hierarchical earns its cost only when the routing genuinely needs judgement.
""")

The third question decides most real cases and is the one people skip. If the routing rule can be written down, a flow applies it correctly every time for zero tokens - and a manager agent applies it correctly most of the time for the price of a model call per decision.

The fourth question is included because it is the one people use, and it decides nothing. Needing different agents tells you about the crew's composition, not about which process should order it.

The mistake this prevents

The mistake is reading hierarchical as the advanced option and sequential as the beginner one. They are different tools for different structures. A workflow with a known order run hierarchically is paying a manager to rediscover the order you already knew.

Takeaway

Choose the process from the structure of the work. If the routing rule is writable, write it - the manager's only justification is routing that genuinely requires judgement.

Mark complete