refactor: refine EAC year difference calculation logic and add an explanatory comment for EM.

src/equipment/service.py

@@ -391,10 +391,6 @@ async def get_top_10_economic_life(*, db_session: DbSession, common) -> list[Equ
     query = (
         query.add_columns(
             case(
-                (
-                    (current_year - Equipment.minimum_eac_year) >= 0,
-                    (current_year - Equipment.minimum_eac_year),
-                ),
                 (
                     (Equipment.minimum_eac_year - current_year) >= 0,
                     (Equipment.minimum_eac_year - current_year),
@@ -427,10 +423,6 @@ async def get_top_10_replacement_priorities(*, db_session: DbSession, common) ->
     query = (
         query.add_columns(
             case(
-                (
-                    (current_year - Equipment.minimum_eac_year) >= 0,
-                    (current_year - Equipment.minimum_eac_year),
-                ),
                 (
                     (Equipment.minimum_eac_year - current_year) >= 0,
                     (Equipment.minimum_eac_year - current_year),

src/modules/equipment/where_query_sql.py

@@ -14,7 +14,7 @@ def get_where_query_sql(assetnum, worktype):
         )
         )
     """
-
+    # EM = Emergency Maintainance 
     return where_query
 
 def get_where_query_sql_all_worktype(assetnum):