개요 (Overview)
Category 7 covers emissions from employees commuting between home and their work site. Two calculation methods are used: distance-based (per-employee commute survey: transport mode and one-way distance) and fuel-efficiency-based (company-operated group vehicles such as shuttle buses, deriving fuel use from distance and fuel economy). Response-rate extrapolation applies only to the distance-based method; group commuting is a complete per-vehicle census, so no correction concept exists there.
Distance-Based Formula
연간 통근 거리 = 편도 거리 × 왕복 계수(왕복이면 2) × 연간 근무일수
배출량 = 연간 통근 거리 × 교통수단별 배출계수 (인·km당)Annual emissions per employee: annual commute distance = one-way distance × round-trip factor (2 when round trip) × annual working days; emissions = annual distance × the transport mode's per-person-km emission factor. Working days come from the site's registered per-year value (falling back to the corporation's when the site has none).
Response-Rate Extrapolation
응답률 = 설문 응답 임직원 수 ÷ 사업장 등록 임직원 수 (사업장 × 연도 단위)
전체 배출량 = 응답자 배출량 합계 ÷ 응답률 (0 < 응답률 < 1 인 경우에만)핵심 규칙:
Commute surveys rarely cover the full workforce, so respondent-only totals under-report. The response rate = distinct survey respondents ÷ the site's registered headcount, computed per site per year; the full-workforce estimate = respondent emissions ÷ rate, applied only when 0 < rate < 1. A rate ≥ 1 means respondents already cover (or exceed) the registered workforce, so no scaling is applied — though a rate above 1 signals headcount under-registration. Scaling happens once at calculation time and is persisted with the result; it is never re-applied at read time.
선행 조건 (Prerequisites)
Distance-based calculation and response-rate extrapolation require per-site, per-year registration of headcount (the rate's denominator — if missing or zero, the rate is undefined and no extrapolation occurs) and working days (required for annual distance; if absent at both site and corporation level, emissions cannot be calculated).
Data-Quality Rules
Keep registered headcount ≥ actual respondents (a rate above 1 means under-registration, and that site-year silently remains unscaled — an under-reporting risk). A headcount of 0 means "not registered", not "no employees": any site with commute data must have its real headcount registered. Assign employees to the site they actually commute to — lumping them under a headquarters site distorts that site's rate and empties the numerator elsewhere. After correcting headcount or working days, recalculate the affected site-years, since the scaling is persisted at calculation time.
Aggregation Principle
All Scope 3 aggregation surfaces (dashboards, reports) sum the stored calculated values. Adjustments including response-rate scaling are already baked in at calculation time, so no multiplier is re-applied at read time. This principle is limited to Scope 3; Scope 1·2 collection and aggregation follow a different flow.
Related Documents
- Scope 3 Categories Overview — where to start among the 15 categories
- Emission Factors — sources and data tiers of the per-mode factors
- Scope 1·2 Emissions Calculation Methodology — fuel combustion for shuttle-bus commuting