As a sustainability data engineer, I want to model PCF values according to ISO 14067, in order to provide standardized CO₂ footprint data in DPP context. Currently, there is no structured way to represent PCF metrics and lifecycle phases. The solution should include a ProductCarbonFootprintBuilder and support for total CO₂ equivalent per unit and lifecycle phase breakdown.
# Motivation As a sustainability data engineer, I want to model PCF values according to ISO 14067, In order to provide standardized CO₂ footprint data in DPP context. **Is your feature request related to a problem? Please describe.** There is no structured way to represent PCF metrics and lifecycle phases. **Describe the solution you'd like** Implement: - `ProductCarbonFootprintBuilder` - Support for: - Total CO₂ equivalent per unit - Lifecycle phase breakdown - Calculation methodology reference - Validation rules: - Numeric consistency - Unit enforcement (kg CO₂e) - Mandatory methodological metadata **Describe alternatives you've considered** Generic numeric property modeling. Rejected due to regulatory sensitivity. **Additional context** Will be required for ESPR-regulated product categories. ## Acceptance Criteria - PCF builder implemented - Lifecycle phase modeling supported - Validation rules implemented - ISO-aligned example provided