Validation Engine in OpenConstructionERP

Philosophy

"Validation is a first-class citizen." Every BOQ import (Excel/CSV/GAEB X83/X84) runs the configured rule packs at import time, so violations surface immediately — not when a user is staring at row 452.

Built-in rule packs

Pack	Checks
boq_quality	required fields, unit consistency, duplicate codes, quantity sanity
DIN 276	cost-group codes valid, hierarchy consistent
NRM	element codes, measurement rules
GAEB	X83/X84 structure, item references
MasterFormat / DPGF	classification codes

Configure the default set via OE_DEFAULT_VALIDATION_RULE_SETS (default ["boq_quality"]); run on demand with POST /api/v1/boqs/{id}/validate/.

Writing custom rules

A rule is: condition + severity + message. Example patterns:

# pseudo-rule: labour share sanity on a BOQ line
def rule_labour_share(line):
    labour = line.components_labour_cost
    total = line.rate
    if total > 0 and labour / total > 0.95:
        return {"severity": "warning",
                "message": f"Line {line.code}: labour is {labour/total:.0%} of rate"}

Reconciliation rules (the ones that actually catch data problems):

• qty × unit_price = cost per component line (tolerance ±0.01 or rounding-aware).
• Σ components = total_resource_cost_per_position (markup applied on top).
• classification non-empty at every tree level.
• no negative quantities outside documented deduction lines.

Where validation plugs in

1. Import gate — import_inline_validation (env) runs packs during upload.
2. On demand — /boqs/{id}/validate/ returns violations with severity.
3. Continuous — the BOQ quality score updates live as the editor changes lines.

Best practices

1. Fail imports on error-severity, warn on warning — never block a user silently.
2. Keep rule messages actionable: name the row, the expected value, the found value.
3. Version rule packs with the standards they encode (DIN 276:2018-12, NRM2, …).
4. Use validation as the QA agent's deterministic backbone (see ai-agent-orchestration).