IDS Checker

Business Case

Problem Statement

BIM data validation challenges:

• Inconsistent model information
• Missing required properties
• Non-compliant data deliveries
• Manual validation is time-consuming

Solution

Automated IDS (Information Delivery Specification) checking system to validate BIM models against defined requirements.

Technical Implementation

python
import pandas as pd
from typing import Dict, Any, List, Optional
from dataclasses import dataclass, field
from datetime import datetime
from enum import Enum
import re


class RequirementType(Enum):
    PROPERTY = "property"
    CLASSIFICATION = "classification"
    MATERIAL = "material"
    ATTRIBUTE = "attribute"
    RELATION = "relation"


class Facet(Enum):
    ENTITY = "entity"
    PROPERTY_SET = "property_set"
    PROPERTY = "property"
    CLASSIFICATION = "classification"
    MATERIAL = "material"
    PART_OF = "part_of"


class Cardinality(Enum):
    REQUIRED = "required"
    OPTIONAL = "optional"
    PROHIBITED = "prohibited"


class CheckResult(Enum):
    PASS = "pass"
    FAIL = "fail"
    WARNING = "warning"
    NOT_APPLICABLE = "n/a"


@dataclass
class IDSRequirement:
    req_id: str
    name: str
    description: str
    applicability: Dict[str, Any]  # Which elements this applies to
    requirements: List[Dict[str, Any]]  # What is required
    cardinality: Cardinality = Cardinality.REQUIRED


@dataclass
class ValidationResult:
    element_id: str
    element_type: str
    requirement_id: str
    result: CheckResult
    message: str
    details: Dict[str, Any] = field(default_factory=dict)


@dataclass
class IDSSpecification:
    spec_id: str
    name: str
    version: str
    purpose: str
    requirements: List[IDSRequirement] = field(default_factory=list)


class IDSChecker:
    """Check BIM data against IDS (Information Delivery Specification)."""

    def __init__(self, spec_name: str):
        self.spec_name = spec_name
        self.specifications: Dict[str, IDSSpecification] = {}
        self.results: List[ValidationResult] = []

    def create_specification(self, spec_id: str, name: str,
                             version: str = "1.0", purpose: str = "") -> IDSSpecification:
        """Create new IDS specification."""

        spec = IDSSpecification(
            spec_id=spec_id,
            name=name,
            version=version,
            purpose=purpose
        )
        self.specifications[spec_id] = spec
        return spec

    def add_requirement(self, spec_id: str, requirement: IDSRequirement):
        """Add requirement to specification."""

        if spec_id in self.specifications:
            self.specifications[spec_id].requirements.append(requirement)

    def add_property_requirement(self, spec_id: str, req_id: str, name: str,
                                  entity_type: str, property_set: str,
                                  property_name: str, data_type: str = None,
                                  value_pattern: str = None,
                                  cardinality: Cardinality = Cardinality.REQUIRED):
        """Add property requirement."""

        requirement = IDSRequirement(
            req_id=req_id,
            name=name,
            description=f"Property {property_name} in {property_set}",
            applicability={'entity': entity_type},
            requirements=[{
                'type': RequirementType.PROPERTY.value,
                'property_set': property_set,
                'property_name': property_name,
                'data_type': data_type,
                'value_pattern': value_pattern
            }],
            cardinality=cardinality
        )
        self.add_requirement(spec_id, requirement)

    def add_classification_requirement(self, spec_id: str, req_id: str, name: str,
                                        entity_type: str, system: str,
                                        value_pattern: str = None,
                                        cardinality: Cardinality = Cardinality.REQUIRED):
        """Add classification requirement."""

        requirement = IDSRequirement(
            req_id=req_id,
            name=name,
            description=f"Classification from {system}",
            applicability={'entity': entity_type},
            requirements=[{
                'type': RequirementType.CLASSIFICATION.value,
                'system': system,
                'value_pattern': value_pattern
            }],
            cardinality=cardinality
        )
        self.add_requirement(spec_id, requirement)

    def create_standard_cobie_spec(self) -> str:
        """Create standard COBie specification."""

        spec = self.create_specification(
            "COBIE_BASIC",
            "COBie Basic Requirements",
            "1.0",
            "Basic COBie data requirements for facility handover"
        )

        # Space requirements
        self.add_property_requirement("COBIE_BASIC", "CB-SP-01", "Space Name",
                                       "IfcSpace", "Pset_SpaceCommon", "Name")
        self.add_property_requirement("COBIE_BASIC", "CB-SP-02", "Space Number",
                                       "IfcSpace", "COBie_Space", "SpaceNumber")
        self.add_property_requirement("COBIE_BASIC", "CB-SP-03", "Room Tag",
                                       "IfcSpace", "COBie_Space", "RoomTag")

        # Component requirements
        self.add_property_requirement("COBIE_BASIC", "CB-CO-01", "Component Name",
                                       "IfcElement", "COBie_Component", "Name")
        self.add_property_requirement("COBIE_BASIC", "CB-CO-02", "Component Type",
                                       "IfcElement", "COBie_Component", "TypeName")
        self.add_property_requirement("COBIE_BASIC", "CB-CO-03", "Serial Number",
                                       "IfcElement", "COBie_Component", "SerialNumber",
                                       cardinality=Cardinality.OPTIONAL)

        # Type requirements
        self.add_property_requirement("COBIE_BASIC", "CB-TY-01", "Type Name",
                                       "IfcTypeObject", "COBie_Type", "Name")
        self.add_property_requirement("COBIE_BASIC", "CB-TY-02", "Manufacturer",
                                       "IfcTypeObject", "COBie_Type", "Manufacturer")
        self.add_property_requirement("COBIE_BASIC", "CB-TY-03", "Model Number",
                                       "IfcTypeObject", "COBie_Type", "ModelNumber")

        return "COBIE_BASIC"

    def create_standard_lod_spec(self, lod_level: int = 300) -> str:
        """Create standard LOD specification."""

        spec_id = f"LOD_{lod_level}"
        spec = self.create_specification(
            spec_id,
            f"LOD {lod_level} Requirements",
            "1.0",
            f"Level of Development {lod_level} requirements"
        )

        if lod_level >= 200:
            self.add_property_requirement(spec_id, f"LOD-{lod_level}-01",
                                           "Element must have type",
                                           "IfcElement", "Pset_ElementCommon", "Type")

        if lod_level >= 300:
            self.add_property_requirement(spec_id, f"LOD-{lod_level}-02",
                                           "Element must have dimensions",
                                           "IfcElement", "BaseQuantities", "Length")
            self.add_property_requirement(spec_id, f"LOD-{lod_level}-03",
                                           "Material assignment",
                                           "IfcElement", "Pset_MaterialCommon", "Material")

        if lod_level >= 350:
            self.add_property_requirement(spec_id, f"LOD-{lod_level}-04",
                                           "Fire rating",
                                           "IfcElement", "Pset_ElementCommon", "FireRating",
                                           cardinality=Cardinality.OPTIONAL)
            self.add_classification_requirement(spec_id, f"LOD-{lod_level}-05",
                                                 "Uniformat classification",
                                                 "IfcElement", "Uniformat")

        return spec_id

    def check_element(self, element: Dict[str, Any],
                      spec_id: str) -> List[ValidationResult]:
        """Check single element against specification."""

        results = []

        if spec_id not in self.specifications:
            return results

        spec = self.specifications[spec_id]

        for req in spec.requirements:
            # Check applicability
            if not self._matches_applicability(element, req.applicability):
                continue

            # Check requirements
            for req_def in req.requirements:
                result = self._check_requirement(element, req, req_def)
                results.append(result)

        return results

    def _matches_applicability(self, element: Dict[str, Any],
                                applicability: Dict[str, Any]) -> bool:
        """Check if element matches applicability criteria."""

        entity_filter = applicability.get('entity')
        if entity_filter:
            element_type = element.get('type', '')
            if entity_filter not in element_type:
                return False

        return True

    def _check_requirement(self, element: Dict[str, Any],
                           req: IDSRequirement,
                           req_def: Dict[str, Any]) -> ValidationResult:
        """Check single requirement."""

        req_type = req_def.get('type')

        if req_type == RequirementType.PROPERTY.value:
            return self._check_property_requirement(element, req, req_def)
        elif req_type == RequirementType.CLASSIFICATION.value:
            return self._check_classification_requirement(element, req, req_def)

        return ValidationResult(
            element_id=element.get('id', ''),
            element_type=element.get('type', ''),
            requirement_id=req.req_id,
            result=CheckResult.NOT_APPLICABLE,
            message="Unknown requirement type"
        )

    def _check_property_requirement(self, element: Dict[str, Any],
                                     req: IDSRequirement,
                                     req_def: Dict[str, Any]) -> ValidationResult:
        """Check property requirement."""

        pset_name = req_def.get('property_set')
        prop_name = req_def.get('property_name')
        value_pattern = req_def.get('value_pattern')

        # Get property value
        properties = element.get('properties', {})
        pset = properties.get(pset_name, {})
        value = pset.get(prop_name)

        result = ValidationResult(
            element_id=element.get('id', ''),
            element_type=element.get('type', ''),
            requirement_id=req.req_id,
            result=CheckResult.PASS,
            message="",
            details={'property_set': pset_name, 'property': prop_name, 'value': value}
        )

        # Check if property exists
        if value is None:
            if req.cardinality == Cardinality.REQUIRED:
                result.result = CheckResult.FAIL
                result.message = f"Missing required property: {pset_name}.{prop_name}"
            elif req.cardinality == Cardinality.PROHIBITED:
                result.result = CheckResult.PASS
                result.message = "Prohibited property correctly absent"
            else:
                result.result = CheckResult.WARNING
                result.message = f"Optional property missing: {pset_name}.{prop_name}"
            return result

        # Check if property should not exist
        if req.cardinality == Cardinality.PROHIBITED:
            result.result = CheckResult.FAIL
            result.message = f"Prohibited property exists: {pset_name}.{prop_name}"
            return result

        # Check value pattern
        if value_pattern:
            if not re.match(value_pattern, str(value)):
                result.result = CheckResult.FAIL
                result.message = f"Value '{value}' does not match pattern '{value_pattern}'"
                return result

        result.message = f"Property {prop_name} = {value}"
        return result

    def _check_classification_requirement(self, element: Dict[str, Any],
                                           req: IDSRequirement,
                                           req_def: Dict[str, Any]) -> ValidationResult:
        """Check classification requirement."""

        system = req_def.get('system')
        value_pattern = req_def.get('value_pattern')

        classifications = element.get('classifications', {})
        value = classifications.get(system)

        result = ValidationResult(
            element_id=element.get('id', ''),
            element_type=element.get('type', ''),
            requirement_id=req.req_id,
            result=CheckResult.PASS,
            message="",
            details={'system': system, 'value': value}
        )

        if value is None:
            if req.cardinality == Cardinality.REQUIRED:
                result.result = CheckResult.FAIL
                result.message = f"Missing classification: {system}"
            else:
                result.result = CheckResult.WARNING
                result.message = f"Optional classification missing: {system}"
            return result

        if value_pattern and not re.match(value_pattern, str(value)):
            result.result = CheckResult.FAIL
            result.message = f"Classification '{value}' does not match pattern"
            return result

        result.message = f"Classification {system} = {value}"
        return result

    def check_model(self, elements: List[Dict[str, Any]],
                    spec_id: str) -> Dict[str, Any]:
        """Check all elements against specification."""

        self.results = []

        for element in elements:
            element_results = self.check_element(element, spec_id)
            self.results.extend(element_results)

        # Summarize results
        pass_count = sum(1 for r in self.results if r.result == CheckResult.PASS)
        fail_count = sum(1 for r in self.results if r.result == CheckResult.FAIL)
        warning_count = sum(1 for r in self.results if r.result == CheckResult.WARNING)

        return {
            'specification': spec_id,
            'elements_checked': len(elements),
            'total_checks': len(self.results),
            'passed': pass_count,
            'failed': fail_count,
            'warnings': warning_count,
            'compliance_rate': round(pass_count / len(self.results) * 100, 1) if self.results else 0,
            'status': 'COMPLIANT' if fail_count == 0 else 'NON-COMPLIANT'
        }

    def get_failed_checks(self) -> List[Dict[str, Any]]:
        """Get list of failed checks."""

        return [
            {
                'element_id': r.element_id,
                'element_type': r.element_type,
                'requirement': r.requirement_id,
                'message': r.message,
                'details': r.details
            }
            for r in self.results if r.result == CheckResult.FAIL
        ]

    def export_to_excel(self, output_path: str) -> str:
        """Export validation results to Excel."""

        with pd.ExcelWriter(output_path, engine='openpyxl') as writer:
            # Summary
            summary = {
                'Total Checks': len(self.results),
                'Passed': sum(1 for r in self.results if r.result == CheckResult.PASS),
                'Failed': sum(1 for r in self.results if r.result == CheckResult.FAIL),
                'Warnings': sum(1 for r in self.results if r.result == CheckResult.WARNING)
            }
            summary_df = pd.DataFrame([summary])
            summary_df.to_excel(writer, sheet_name='Summary', index=False)

            # All results
            results_df = pd.DataFrame([{
                'Element ID': r.element_id,
                'Element Type': r.element_type,
                'Requirement': r.requirement_id,
                'Result': r.result.value,
                'Message': r.message
            } for r in self.results])
            results_df.to_excel(writer, sheet_name='All Results', index=False)

            # Failed only
            failed_df = pd.DataFrame(self.get_failed_checks())
            if not failed_df.empty:
                failed_df.to_excel(writer, sheet_name='Failed', index=False)

        return output_path

Quick Start

python
# Create IDS checker
checker = IDSChecker("Project BIM Validation")

# Create COBie specification
cobie_spec = checker.create_standard_cobie_spec()

# Sample BIM elements
elements = [
    {
        'id': 'Space_001',
        'type': 'IfcSpace',
        'properties': {
            'Pset_SpaceCommon': {'Name': 'Office 101'},
            'COBie_Space': {'SpaceNumber': 'SP-101', 'RoomTag': 'A101'}
        }
    },
    {
        'id': 'Door_001',
        'type': 'IfcDoor',
        'properties': {
            'COBie_Component': {'Name': 'Door 1', 'TypeName': 'Single Door'}
        }
    }
]

# Check model
results = checker.check_model(elements, cobie_spec)
print(f"Compliance: {results['compliance_rate']}%")
print(f"Status: {results['status']}")

Common Use Cases

1. LOD Validation

python
lod_spec = checker.create_standard_lod_spec(350)
results = checker.check_model(elements, lod_spec)

2. Custom Requirement

python
checker.add_property_requirement(
    "COBIE_BASIC", "CB-CUSTOM-01", "Fire Rating Required",
    "IfcWall", "Pset_WallCommon", "FireRating",
    value_pattern=r"^\d+\s*hr$"
)

3. Get Failed Items

python
failed = checker.get_failed_checks()
for item in failed:
    print(f"{item['element_id']}: {item['message']}")

Resources

• DDC Book: Chapter 4.3 - Automated ETL Pipeline for Data Validation
• buildingSMART IDS: https://technical.buildingsmart.org/projects/information-delivery-specification-ids/
• Website: https://datadrivenconstruction.io