相关的表：
ekko:采购凭证抬头表 用于判断是否委外
ekpo:采购凭证行项目表 用于判断是否委外以及委外采购的数量
resb:获取委外采购单中bom的相应预留
mseg:获取已经委外原材料出库给供应商的批次
mslb:获取提供给供应商的库存以及批次
bapi
BAPI_GOODSMVT_CREATE：过账bapi
相关移动类型
101：采购收货过账
541：委外原材料出库过账（这里的逻辑默认已经原料出库了）
543：消耗委外原材料出库到供应商的库存的数据
委外流程
创建委外采购单
委外采购单：4500000908
因为bom组件过多，我用作测试的话，就在采购订单中删除了很多bom组件，只留了两个
委外原材料过账
审批后进行委外过账，我这边也是通过接口过账的，也是用的BAPI_GOODSMVT_CREATE这个bapi,移动类型541
过账后你会在mmbe里查看物料的库存时发现有提供给供应商的库存
委外采购过账
因为涉及系统之间的传输，所以并不能完整给出代码，但是主体处理是没有问题的，部分参数我也写死了，根据自己需要改写即可
DATA: ls_header LIKE bapi2017_gm_head_01,
lv_code LIKE bapi2017_gm_code VALUE '01',
lv_doc TYPE bapi2017_gm_head_ret-mat_doc,
lv_year TYPE bapi2017_gm_head_ret-doc_year,
lt_item LIKE bapi2017_gm_item_create OCCURS 0 WITH HEADER LINE,
lt_ret LIKE bapiret2 OCCURS 0 WITH HEADER LINE.
DATA: lv_outfm TYPE mseg-menge,
lv_outfz TYPE mseg-menge.
DATA: lv_line_id TYPE mseg-line_id VALUE '000000',
lv_parent_id TYPE mseg-parent_id VALUE '000000',
lv_line_depth TYPE mseg-line_depth VALUE '00'.
"判断 是否是 委外采购订单收货
SELECT
FROM ekko
INNER JOIN ekpo
ON ekko~ebeln EQ ekpo~ebeln
FIELDS
ekko~ebeln,
ekpo~ebelp,
ekpo~matnr,
ekko~bsart,
ekpo~pstyp,
ekpo~menge
WHERE ekpo~ebeln EQ '4500000908'
AND ekpo~ebelp EQ '00010'
AND ekpo~matnr EQ '采购单上的物料号'
AND ekko~bsart EQ 'Z003'
AND ekpo~pstyp EQ '3'
INTO TABLE @DATA(lt_outpo).
IF lt_outpo IS NOT INITIAL. " 该采购单是委外采购单
"获取委外采购单的相应bom预留 以及 对应批次
SELECT
FROM resb
INNER JOIN mseg
ON mseg~ebeln EQ resb~ebeln
AND mseg~ebelp EQ resb~ebelp
AND mseg~lifnr eq resb~lifnr
AND mseg~matnr eq resb~matnr
FIELDS
mseg~matnr,
resb~erfmg,
resb~ebeln,
resb~ebelp,
mseg~werks,
mseg~lgort,
mseg~sobkz,
mseg~charg,
mseg~lifnr,
resb~meins
WHERE resb~ebeln EQ '4500000908'
AND resb~ebelp EQ '00010'
AND mseg~lifnr EQ '30108'
AND mseg~sobkz = 'O'
INTO TABLE @DATA(lt_outbom).
"获取提供给的供应商库存
SELECT
FROM mslb
FIELDS
mslb~matnr,
mslb~charg,
mslb~werks,
mslb~sobkz,
mslb~lifnr,
mslb~lblab,
mslb~ersda
WHERE mslb~lifnr EQ '30108'
INTO TABLE @DATA(lt_outinv).
SORT lt_outinv BY ersda ASCENDING.
ENDIF.
lt_item-po_number = '4500000908'.
lt_item-po_item = '00010'.
lt_item-material = '采购单上的物料号'.
lt_item-vendor = '30108'.
lt_item-entry_qnt = '5'.
lt_item-entry_uom = '物料单位'.
lt_item-plant = '工厂'.
lt_item-stge_loc = '存储地点'.
lt_item-move_type = '101'.
lt_item-vendrbatch = '供应商批次'.
lt_item-batch = '内部批次'.
lv_xchpf = 'X'.
lv_line_id = lv_line_id + 1.
lv_parent_id = lv_line_id.
lt_item-line_id = lv_parent_id. " 父项目
_conv_matnr: 'IN' lt_item-material.
_conv_alpha: 'IN' lt_item-vendor.
_conv_alpha: 'IN' lt_item-po_number.
APPEND lt_item.
CLEAR: lt_item.
"上面的过账一般采购收货都是一样的 ，委外的区别就在下面这个循环，需要将bom组件的数据也写入
IF lt_outpo IS NOT INITIAL. " 该采购单是委外采购单 需要填入明细数据 移动类型为543
lv_outfz = '采购收货的数量'. " 过账的数量 用作分子
READ TABLE lt_outpo INTO DATA(ls_outpo) WITH KEY ebeln = '4500000908' ebelp = '00010'.
IF sy-subrc EQ 0.
lv_outfm = ls_outpo-menge. " 找出采购单的数量 用作分母
ENDIF.
LOOP AT lt_outbom ASSIGNING FIELD-SYMBOL(<fs_outbom>) WHERE ebeln = '4500000908' AND ebelp = '00010'. " 获取bom预留
lt_item-move_type = '543'. " 移动类型
lt_item-material = <fs_outbom>-matnr. " 物料号
lt_item-plant = <fs_outbom>-werks. " 工厂
lt_item-stge_loc = <fs_outbom>-lgort. " 存储字典
lt_item-spec_stock = 'O'. " 特殊库存
lt_item-batch = <fs_outbom>-charg. " 内部批次
lt_item-entry_qnt = lv_outfz / lv_outfm * <fs_outbom>-erfmg. " 过账的成品数量 / 采购的成品数量 * BOM组件的数量
lt_item-entry_uom = <fs_outbom>-meins. " 单位
lt_item-parent_id = lv_parent_id. " 父项目编码
lv_line_id = lv_line_id + 1. " 子项目编号
lt_item-line_id = lv_line_id.
lv_line_depth = '01'.
lt_item-line_depth = lv_line_depth. "bom层次
APPEND lt_item.
CLEAR lt_item.
ENDLOOP.
ENDIF.
clear it_item.
CALL FUNCTION 'BAPI_GOODSMVT_CREATE'
EXPORTING
goodsmvt_header = ls_header
goodsmvt_code = lv_code
IMPORTING
materialdocument = lv_doc
matdocumentyear = lv_year
TABLES
goodsmvt_item = lt_item
return = lt_ret.
IF lv_doc <> ''.
CALL FUNCTION 'BAPI_TRANSACTION_COMMIT'
EXPORTING
wait = 'X'.
ELSE.
CALL FUNCTION 'BAPI_TRANSACTION_ROLLBACK'.
ENDIF.