Rules-Based Automation vs AI: How to Choose an Approach

Séparer les décisions fixes de l'interprétation.

Si une tâche suit des conditions explicites, une approche basée sur des règles peut être simple à expliquer et à tester. S’il s’agit d’un langage varié ou d’entrées ambiguës, une approche assistée peut être intéressante à explorer. Décrivez l'incertitude de la tâche plutôt que de choisir une méthode parce qu'elle est à la mode.

Comparez l'effort opératoire.

Déterminez qui mettra à jour les règles ou révisera les résultats assistés lorsque les exigences changent. Incluez la gestion des exceptions, l’accès et la prise en charge dans la comparaison. Une petite démonstration ne révèle pas tout le travail nécessaire pour maintenir l'approche une fois que d'autres personnes en dépendent.

Pilotez une frontière étroite.

Choisissez une partie représentative du flux de travail et acceptez les critères de révision. Comparez le résultat avec la méthode actuelle. Il peut être utile de combiner des règles explicites avec une assistance, mais chaque composant doit avoir un objectif clair et un propriétaire qui comprend ses limites.

Compare approaches against the same task

Describe the input, required outcome and important exceptions without naming a preferred tool. Implement or describe the simplest reasonable baseline, such as a lookup or explicit rule. Evaluate it on representative examples and record where it fails.

If another approach is considered, use the same cases and review criteria. Compare accuracy where it matters, effort required for checking, response time, access needs, running costs and maintenance responsibilities. Examine how each option behaves outside its intended scope. A combined workflow may use rules for stable boundaries and assistance for ambiguous material, but that arrangement still needs clear ownership and evaluation. Choose based on the observed trade-offs rather than the novelty of the method.

A rules-versus-AI comparison sheet

Complete the comparison before a procurement or implementation commitment. Mark estimates separately from measurements.

• Task definition: input types, intended outputs, operating context and excluded uses.
• Baseline: explicit rules or an existing manual method and its known limitations.
• Candidate: proposed alternative and the specific failure it is intended to address.
• Evaluation results: common cases, important exceptions and unacceptable outcomes.
• Operating implications: review effort, latency, access, cost and maintenance ownership.
• Decision: selected approach, reasons, unresolved assumptions and conditions for reassessment.

Do not compare a polished demo with an undefined baseline

A demonstration chosen for one method may not represent everyday work. Include cases that challenge both options and use criteria agreed in advance. Distinguish a routing error from a harmless difference in wording.

Avoid assuming that a rules-based solution is maintenance-free or that an AI solution will adapt correctly without review. Both can become unsuitable when inputs or policies change. Plan how the chosen approach is tested and updated when the task evolves.

When is a combined approach useful?

Consider it when explicit rules can enforce stable boundaries while another method handles material that needs interpretation. Keep the interfaces between those parts clear. Test the combined workflow as a whole, including what happens when a component produces no usable result.

ILLUSTRATIVE PLANNING EXAMPLE

Example: classifying requests

A request with an explicit department code may be routed with a straightforward rule. Free-text descriptions with inconsistent wording may justify evaluating another method. Test both approaches against representative examples, including incomplete requests. Compare the errors and operating effort that matter to the team rather than assuming a more complex tool is better.

Write down why the chosen approach fits the task, which cases need human handling and what would trigger a review of that decision.

FURTHER READING

Official resources to explore

Explore the related official guidance below. The templates and examples are practical starting points to adapt to your own project.

• NIST AI Risk Management Framework Playbook