app/schemas/suppliers.py

@@ -25,7 +25,7 @@ class SupplierMetric(ApiSchema):
     supplier_score: float | None = None
     risk_score: float | None = None
     main_category_count: int
-    cooperation_count_basis: str = "按近3年采购订单去重单据编号统计"
+    cooperation_count_basis: str = "按自然年度边界采购订单去重单据编号统计"
     anomaly_rate_basis: str = "暂无采购订单/生产批次总量，无法计算真实异常率"
 
 

app/services/conversations.py

@@ -4,7 +4,7 @@ import json
 import logging
 import re
 from collections.abc import AsyncGenerator, Sequence
-from datetime import UTC, date, datetime, timedelta
+from datetime import UTC, date, datetime
 from typing import Any, Literal
 
 from sqlalchemy import delete, func, or_, select
@@ -36,14 +36,14 @@ from app.schemas.risk_prediction import (
 )
 from app.services.database_risk_scoring import DatabaseRiskScoringService
 from app.services.llm_client import LLMClient
-from app.services.purchase_orders import supplier_order_counts
+from app.services.purchase_orders import calendar_year_window, supplier_order_counts
 from app.services.rag import AnomalyCaseRAG
 
 logger = logging.getLogger("dieya_risk_prediction.conversations")
 
 
 class ConversationService:
-    _supplier_history_days = 365 * 3
+    _supplier_history_years = 3
     _engine = BaselineRiskEngine()
     _risk_intents = {
         "assessment",
@@ -582,7 +582,7 @@ class ConversationService:
                 self.session,
                 name,
                 self._supplier_history_start(),
-                datetime.now(UTC).date(),
+                self._supplier_history_end(),
             )
             if hasattr(self, "session")
             else None
@@ -626,9 +626,9 @@ class ConversationService:
             "supplierScore": supplier_dimension.score if supplier_dimension else None,
             "topProblems": problems,
             "suggestions": self._supplier_management_suggestions(tier),
-            "frequencyBasis": "近3年采购订单去重单据数" if has_order_data else "暂无匹配采购订单",
+            "frequencyBasis": "按自然年度边界采购订单去重单据数" if has_order_data else "暂无匹配采购订单",
             "note": (
-                "合作次数按近3年采购订单去重单据编号统计。"
+                "合作次数按自然年度边界采购订单去重单据编号统计。"
                 if has_order_data
                 else "未匹配到该供应商采购订单，不展示合作次数。"
             ),
@@ -938,7 +938,7 @@ class ConversationService:
                 [
                     AnomalyCase.date.is_not(None),
                     AnomalyCase.date >= since,
-                    AnomalyCase.date <= datetime.now(UTC).date(),
+                    AnomalyCase.date <= self._supplier_history_end(),
                 ]
             )
         rows = await self.session.execute(
@@ -1082,7 +1082,7 @@ class ConversationService:
                 self.session,
                 supplier,
                 self._supplier_history_start(),
-                datetime.now(UTC).date(),
+                self._supplier_history_end(),
             )
             if supplier
             else None
@@ -1175,9 +1175,9 @@ class ConversationService:
                         ),
                         tier=tier,
                         suggestion="；".join(self._supplier_management_suggestions(tier)),
-                        frequency_basis="近3年采购订单去重单据数" if cooperation_count else "暂无匹配采购订单",
+                        frequency_basis="按自然年度边界采购订单去重单据数" if cooperation_count else "暂无匹配采购订单",
                         note=(
-                            "合作次数按采购订单去重单据编号统计；异常数仍按近3年异常案例统计。"
+                            "合作次数按自然年度边界采购订单去重单据编号统计；异常数按自然年度边界异常案例统计。"
                             if cooperation_count
                             else "未匹配到该供应商采购订单，不展示合作次数。"
                         ),
@@ -1209,14 +1209,18 @@ class ConversationService:
                 column.ilike(f"%{value}%"),
                 AnomalyCase.date.is_not(None),
                 AnomalyCase.date >= self._supplier_history_start(),
-                AnomalyCase.date <= datetime.now(UTC).date(),
+                AnomalyCase.date <= self._supplier_history_end(),
             )
         )
         return int(count or 0)
 
     @classmethod
     def _supplier_history_start(cls) -> date:
-        return datetime.now(UTC).date() - timedelta(days=cls._supplier_history_days)
+        return calendar_year_window(datetime.now(UTC).date(), cls._supplier_history_years)[0]
+
+    @classmethod
+    def _supplier_history_end(cls) -> date:
+        return calendar_year_window(datetime.now(UTC).date(), cls._supplier_history_years)[1]
 
     async def _supplier_history_stats(
         self,
@@ -1234,7 +1238,7 @@ class ConversationService:
                     column.ilike(f"%{value}%"),
                     AnomalyCase.date.is_not(None),
                     AnomalyCase.date >= self._supplier_history_start(),
-                    AnomalyCase.date <= datetime.now(UTC).date(),
+                    AnomalyCase.date <= self._supplier_history_end(),
                 )
                 .group_by(AnomalyCase.defect_level)
             )
@@ -1354,7 +1358,7 @@ class ConversationService:
                 ),
                 AnomalyCase.date.is_not(None),
                 AnomalyCase.date >= self._supplier_history_start(),
-                AnomalyCase.date <= datetime.now(UTC).date(),
+                AnomalyCase.date <= self._supplier_history_end(),
             )
         )
         return int(count or 0)

app/services/database_risk_scoring.py

@@ -12,7 +12,7 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.domain.model_config import DEFAULT_FREQUENCY_CAP, DEFAULT_FREQUENCY_COEFFICIENT, DEFAULT_WEIGHTS
 from app.domain.risk_engine import RiskLevel
 from app.models.entities import AnomalyCase, RiskModelConfig
-from app.services.purchase_orders import supplier_order_counts
+from app.services.purchase_orders import calendar_year_window, supplier_order_counts
 
 STAGES = ("需求发现", "产品立项", "产品开发", "量产上市", "产品生命管理")
 
@@ -107,8 +107,7 @@ class DatabaseRiskScoringService:
             return await supplier_order_counts(
                 self.session,
                 party_name,
-                self.as_of - timedelta(days=365 * 3),
-                self.as_of,
+                *calendar_year_window(self.as_of, 3),
             )
         except Exception:  # noqa: BLE001 - legacy/test databases may not have the order ledger yet
             return None
@@ -127,7 +126,7 @@ class DatabaseRiskScoringService:
         self.frequency_cap = float(config.frequency_cap)
 
     async def _load_rows(self) -> list[dict[str, Any]]:
-        start = self.as_of - timedelta(days=365 * 3)
+        start, end = calendar_year_window(self.as_of, 3)
         statement = select(
             AnomalyCase.date,
             AnomalyCase.product_name,
@@ -140,7 +139,7 @@ class DatabaseRiskScoringService:
         ).where(
             AnomalyCase.date.is_not(None),
             AnomalyCase.date >= start,
-            AnomalyCase.date <= self.as_of,
+            AnomalyCase.date <= end,
         )
         return [dict(row) for row in (await self.session.execute(statement)).mappings().all()]
 
@@ -200,9 +199,9 @@ class DatabaseRiskScoringService:
             weight=weight,
             status="database",
             reason=(
-                f"近 3 年采购订单 {count} 单，异常案例 {anomaly_count} 条，基础分 {base:g}，α={alpha:.2f}"
+                f"近 3 个自然年度采购订单 {count} 单，异常案例 {anomaly_count} 条，基础分 {base:g}，α={alpha:.2f}"
                 if cooperation_count is not None and cooperation_count > 0
-                else f"近 3 年异常 {count} 条，基础分 {base:g}，α={alpha:.2f}"
+                else f"近 3 个自然年度异常 {count} 条，基础分 {base:g}，α={alpha:.2f}"
             ),
             sample_size=anomaly_count,
             raw_value=count,

app/services/purchase_orders.py

@@ -16,6 +16,20 @@ from sqlalchemy.ext.asyncio import AsyncSession
 from app.models.entities import PurchaseOrderLine
 
 
+def calendar_year_window(as_of: date, years: int = 3) -> tuple[date, date]:
+    """Return the natural-year window used by historical statistics.
+
+    ``years=3`` means the year three calendar years before ``as_of`` through
+    the end of ``as_of``'s calendar year.  For example, an as-of date in 2026
+    uses 2023-01-01 through 2026-12-31, so a partial current year never drops
+    an otherwise valid record merely because of its month/day.
+    """
+
+    if years < 1:
+        raise ValueError("years must be positive")
+    return date(as_of.year - years, 1, 1), date(as_of.year, 12, 31)
+
+
 def clean_text(value: Any) -> str | None:
     if value is None:
         return None

app/services/reports.py

@@ -341,7 +341,7 @@ def build_risk_report_pdf(result: RiskAssessmentResult) -> bytes:
     if (supplier and supplier.supplier_name) or supplier_cards:
         supplier_rows = [["维度", "数值", "说明"]]
         if supplier and supplier.cooperation_count is not None:
-            supplier_rows.append(["合作次数", f"{supplier.cooperation_count} 次", "近三年采购订单去重单据数"])
+            supplier_rows.append(["合作次数", f"{supplier.cooperation_count} 次", "按自然年度边界采购订单去重单据数"])
         if supplier:
             supplier_rows.append(["异常次数", f"{supplier.anomaly_count or 0} 次", "异常案例库统计"])
         if supplier and supplier.alpha is not None:
@@ -572,7 +572,9 @@ def build_risk_report_docx(result: RiskAssessmentResult) -> bytes:
         heading("三、供应商合作频次分析")
         rows = [["维度", "数值", "说明"]]
         if result.supplier_freq and result.supplier_freq.cooperation_count is not None:
-            rows.append(["合作次数", f"{result.supplier_freq.cooperation_count} 次", "近三年采购订单去重单据数"])
+            rows.append(
+                ["合作次数", f"{result.supplier_freq.cooperation_count} 次", "按自然年度边界采购订单去重单据数"]
+            )
         if result.supplier_freq:
             rows.append(["异常次数", f"{result.supplier_freq.anomaly_count or 0} 次", "异常案例库统计"])
         if result.supplier_freq and result.supplier_freq.alpha is not None:

app/services/suppliers.py

@@ -4,7 +4,7 @@ from __future__ import annotations
 
 import re
 from collections import Counter, defaultdict
-from datetime import UTC, date, datetime, timedelta
+from datetime import UTC, date, datetime
 
 from sqlalchemy import func, select
 from sqlalchemy.ext.asyncio import AsyncSession
@@ -20,11 +20,11 @@ from app.schemas.suppliers import (
     SupplierRecentRecord,
 )
 from app.services.database_risk_scoring import DatabaseRiskScoringService, normalize_category
-from app.services.purchase_orders import supplier_order_counts
+from app.services.purchase_orders import calendar_year_window, supplier_order_counts
 
 
 class SupplierProfileService:
-    history_days = 365 * 3
+    history_years = 3
     recent_months = 6
     max_categories = 5
     max_recent_records = 10
@@ -58,14 +58,15 @@ class SupplierProfileService:
         all_rows = await self._load_rows()
         rows = [row for row in all_rows if self.matches(row.get("supplier"), supplier_name)]
         if not rows:
-            raise AppException("供应商不存在或暂无近3年异常记录", code=404, status_code=404)
+            raise AppException("供应商不存在或暂无近3个自然年度异常记录", code=404, status_code=404)
 
         anomaly_total = len(rows)
+        history_start, history_end = calendar_year_window(self.as_of, self.history_years)
         order_count = await supplier_order_counts(
             self.session,
             supplier_name,
-            self.as_of - timedelta(days=self.history_days),
-            self.as_of,
+            history_start,
+            history_end,
         )
         a_count = sum(self.defect_code(row.get("defect_level")) == "A" for row in rows)
         b_count = sum(self.defect_code(row.get("defect_level")) == "B" for row in rows)
@@ -116,7 +117,7 @@ class SupplierProfileService:
             monthly_trend=self._monthly_trend(rows),
             recent_records=self._recent_records(rows),
             factory_recommendations=[],
-            recommendation_note="合作次数按近3年采购订单去重单据编号统计；异常数和供应商层级仍按异常案例库统计。",
+            recommendation_note="合作次数按自然年度边界采购订单去重单据编号统计；异常数和供应商层级仍按异常案例库统计。",
         )
 
     async def _load_supplier_summary(
@@ -130,14 +131,14 @@ class SupplierProfileService:
         the remote PostgreSQL connection.
         """
 
-        start = self.as_of - timedelta(days=self.history_days)
+        start, end = calendar_year_window(self.as_of, self.history_years)
         statement = (
             select(AnomalyCase.supplier, AnomalyCase.defect_level, func.count())
             .where(
                 AnomalyCase.supplier.is_not(None),
                 AnomalyCase.date.is_not(None),
                 AnomalyCase.date >= start,
-                AnomalyCase.date <= self.as_of,
+                AnomalyCase.date <= end,
             )
             .group_by(AnomalyCase.supplier, AnomalyCase.defect_level)
         )
@@ -161,7 +162,7 @@ class SupplierProfileService:
         return grouped
 
     async def _load_rows(self, *, supplier_name: str | None = None) -> list[dict]:
-        start = self.as_of - timedelta(days=self.history_days)
+        start, end = calendar_year_window(self.as_of, self.history_years)
         statement = select(
             AnomalyCase.id,
             AnomalyCase.date,
@@ -175,7 +176,7 @@ class SupplierProfileService:
         ).where(
             AnomalyCase.date.is_not(None),
             AnomalyCase.date >= start,
-            AnomalyCase.date <= self.as_of,
+            AnomalyCase.date <= end,
         )
         if supplier_name:
             statement = statement.where(AnomalyCase.supplier.ilike(f"%{supplier_name}%"))
@@ -223,7 +224,7 @@ class SupplierProfileService:
             "A级": "异常记录 20~60 次，且 A/B 级缺陷占比 < 30%",
             "B级": "异常记录 60~120 次，或 A/B 级缺陷占比 30%~50%",
             "C级": "异常记录 > 120 次，或存在 A 级缺陷，或 A/B 级缺陷占比 > 50%",
-            "新供应商": "近3年异常记录为 0",
+            "新供应商": "近3个自然年度异常记录为 0",
         }[tier]
 
     @classmethod

tests/test_purchase_orders.py

@@ -0,0 +1,15 @@
+from datetime import date
+
+import pytest
+from app.services.purchase_orders import calendar_year_window
+
+
+@pytest.mark.parametrize(
+    ("as_of", "expected"),
+    [
+        (date(2026, 9, 10), (date(2023, 1, 1), date(2026, 12, 31))),
+        (date(2025, 1, 1), (date(2022, 1, 1), date(2025, 12, 31))),
+    ],
+)
+def test_three_year_window_uses_calendar_years(as_of: date, expected: tuple[date, date]) -> None:
+    assert calendar_year_window(as_of, 3) == expected