Rule Types

Type	Purpose	Priority	Success	Failure
GUARD	Block/allow operations	500-1000	Rarely	✅ Yes
VALIDATION	Validate data	300-500	✅ Yes	✅ Yes
CALCULATION	Calculate values	200-300	✅ Yes	Rarely
ACTION	Trigger side effects	50-200	✅ Yes	Sometimes
ASSIGNMENT	Auto-set fields	0-100	✅ Yes	Rarely

GUARD

Purpose: Block/allow operations. If ANY guard blocks, operation stops.

Behavior: Conditions true → failure actions (BLOCK), false → success actions (ALLOW)

Use Cases: Enforce prerequisites, prevent policy violations, require conditions

Examples:

IF newStatus = "RELEASED" AND materialsAvailable = false
THEN BLOCK + SHOW_ERROR

IF orderTotal > creditLimit AND creditCheckRequired = true
THEN BLOCK + NOTIFY approver

Best Practices: High priority (500-1000), clear error messages, actionable guidance, log blocks

Actions: Failure: BLOCK_TRANSITION, SHOW_ERROR, LOG, NOTIFY

VALIDATION

Purpose: Validate data without hard blocking (soft stop via warnings/flags)

Use Cases: Data quality, required fields, business logic, approval triggers

Examples:

IF orderTotal > 10000
THEN SET_FIELD approvalRequired=true, NOTIFY approver

IF shipDate < orderDate
THEN SHOW_ERROR, LOG

Best Practices: Priority 300-500, accumulate errors, distinguish warnings from errors

Actions: Success/Failure: SET_FIELD, SHOW_ERROR, SHOW_WARNING, LOG, NOTIFY

GUARD vs VALIDATION: GUARD = hard stop (blocks), VALIDATION = soft stop (warns/flags)

CALCULATION

Purpose: Calculate and set derived values. Runs after validation, before actions.

Use Cases: Pricing, discounts, tax, scoring, date calculations

Examples:

IF orderQuantity >= 100
THEN SET_FIELD discount = orderTotal * 0.15

IF customer.region = "CA"
THEN SET_FIELD taxAmount = subtotal * 0.0825

Best Practices: Priority 200-300, handle null/zero, round financials, document formulas

Actions: Success: SET_FIELD, LOG

ACTION

Purpose: Trigger side effects (notifications, webhooks, events, logging). Doesn't modify entity data.

Use Cases: Notifications, external APIs, domain events, audit trails

Examples:

IF status = "CONFIRMED"
THEN NOTIFY customer, LOG confirmation

IF orderTotal > 50000
THEN NOTIFY manager, CALL_WEBHOOK

Best Practices: Priority 50-200, handle webhook failures gracefully, avoid spam, include context

Actions: Success: NOTIFY, CALL_WEBHOOK, EMIT_EVENT, LOG, SHOW_INFO

ASSIGNMENT

Purpose: Auto-set field values. Runs last (lowest priority).

Use Cases: Auto-assign, defaults, timestamps, metadata, ownership

Examples:

IF priority = "HIGH" AND assignedTo IS_EMPTY
THEN SET_FIELD assignedTo = {{nextAvailableAgent}}

IF status CHANGED
THEN SET_FIELD lastStatusChange={{now}}, lastModifiedBy={{user.id}}

Best Practices: Priority 0-100, check empty first (don't overwrite), use special values, log assignments

Actions: Success: SET_FIELD, LOG, NOTIFY

Choosing the Right Type

Decision Tree:

• Preventing operation? → GUARD
• Checking validity? → VALIDATION
• Calculating value? → CALCULATION
• Auto-setting field? → ASSIGNMENT
• Otherwise → ACTION

Common Combinations:

Approval Workflow: VALIDATION(400) → CALCULATION(250) → ASSIGNMENT(50) → ACTION(25)

Order Processing: GUARD(800) → VALIDATION(400) → CALCULATION(250) → ASSIGNMENT(50) → ACTION(25)

Work Order Release: GUARD(900,850) → VALIDATION(400) → ASSIGNMENT(50) → ACTION(25)

Execution Order

Rules execute by priority (highest first):

1000-900: GUARD (critical/standard)
500-400: VALIDATION (required/standard)
300-250: CALCULATION (dependent/primary)
200-100: ACTION (high-priority), ASSIGNMENT
50-25: ACTION (notifications/logging)

Same priority: Order deterministic but not guaranteed.

Key Considerations

Type	Warning	Best Practice
GUARD	Blocking is permanent	Clear messages, test thoroughly, monitor false positives
VALIDATION	Can accumulate errors	Distinguish warnings/errors, avoid warning fatigue
CALCULATION	Handle edge cases	Test null/zero, round financials, document formulas
ACTION	Webhooks may fail	Handle gracefully, avoid spam, include context
ASSIGNMENT	Don't overwrite input	Check before setting, allow override, log changes

Next Steps

• Creating Rules - Step-by-step guide to creating rules
• Conditions - Build conditional logic
• Actions - Configure actions for each type