| Status | |
|---|---|
| Owner | Bernard Ng |
| Stakeholders |
Purpose
The purpose of this document is to define the conversion approach to create Business Partners - FI Vendor (FLVN00) in S/4 HANA.
Business Partner - FI Vendor Role captures the vendor’s FI data attributes such as Reconciliation Account, Tax Code, Payment data, etc. at the Company Code level.
Conversion Scope
The scope of this document covers the approach for converting active vendors from Legacy Source Systems into S/4HANA following the Master Data Design Standard # 3018.
There is high dependency on Business Partner General Role / data as per CNV-3007 Business Partners - General (Role 000000) which covers the overall scope and relevancy rules. Deduplication also determines the legacy vs target migration records at General level and subsequent Company code level. Example if 2 vendor records are combined at General level, the same has to be done at Company level. The values to be combined or overwritten has to be confirmed by data owners if values are different eg payment term , payment method, etc.
Fields that are not in company code level will be categorized as 'general' and will be covered in MDS / CNV # 3007.
Relevancy rule :
- Extract all records from legacy tables LFB1 and LFBW by matching LIFNR with final in-scope legacy records (LFA1-LIFNR) after deduplication is done in CNV-3007. BUKRS is based on in scope company code mapping.
- Exclude blocked vendors (LFB1-SPERR <> blank) and deleted vendors (LFB1-LOEVM <> blank)
- Extract all records from legacy tables STXH and STXL where TDOBJECT = LFB1
| Source | Scope | Source Approx No. of Records | Target System | Target Approx No. of Records |
|---|---|---|---|---|
| PF2/WP2 |
| 53,000 | S4 | 53,000 |
Additional Information
Multi-language Requirement
Based on legacy or to-be design, there may be multiple language texts (table STXH and STXL)
Document Management
N/A
Legal Requirement
N/A
Special Requirements
N/A
Target Design
With Functional input, document the technical design of the target fields that are in the scope of this document.
The technical design of the target for this conversion approach.
| Table | Field | Data Element | Field Description | Data Type | Length | Requirement |
|---|---|---|---|---|---|---|
| LFB1 | LIFNR | LIFNR | Vendor | CHAR | 10 | Mandatory with mapping |
| LFB1 | BUKRS | BUKRS | Company code | CHAR | 4 | Mandatory with mapping |
| LFB1 | ZUAWA | DZUAWA | Key for Sorting According to Assignment | CHAR | 3 | Mandatory with mapping |
| LFB1 | AKONT | AKONT | Reconciliation Account* | CHAR | 10 | Mandatory with mapping |
| LFB1 | FDGRV | FDGRV | Planning Group | CHAR | 10 | Mandatory with mapping |
| LFB1 | LNRZB | LNRZB | Account Number of the Alternative Payee | CHAR | 10 | Optional |
| LFB1 | ZAHLS | DZAHLS | Payment Block (Key) | CHAR | 1 | Optional with mapping |
| LFB1 | ZTERM | DZTERM | Terms of Payment Key | CHAR | 4 | Optional with mapping |
| LFB1 | REPRF | REPRF | Check Double Invoice | CHAR | 1 | Optional |
| LFB1 | ALTKN | ALTKN | Previous Account Number | CHAR | 10 | Optional |
| LFB1 | HBKID | HBKID | Short Key for a House Bank | CHAR | 4 | Optional |
| LFB1 | INTAD | INTAD | Clerks internet address | CHAR | 130 | Optional |
| LFB1 | QSREC | QSREC | Type of Recipient | CHAR | 2 | Optional |
| LFB1 | TOGRR | TOGRR | Tolerance Group in Invoice Verification | CHAR | 3 | Optional |
| LFB1 | XLFZB | XLFZB | Indicator: Alternative Payee Using Account Number | CHAR | 1 | Optional |
| LFB1 | ZWELS | ZWELS | Payment Method | CHAR | 10 | Optional |
| LFB1 | QSSKZ | QSSKZ | Withholding Tax Code | CHAR | 2 | Optional |
| LFB1 | UZAWE | UZAWE | Payment Method Supplement | CHAR | 2 | Optional |
| LFBW | LIFNR | LIFNR | Vendor | CHAR | 10 | Mandatory with mapping |
| LFBW | BUKRS | BUKRS | Company code | CHAR | 4 | Mandatory with mapping |
| LFBW | WITHT | WITHT | Withholding Tax Type* | CHAR | 2 | Optional with mapping |
| LFBW | WT_SUBJCT | WT_SUBJCT | Subject | CHAR | 1 | Optional |
| LFBW | QSREC | QSREC | Type of recipient | CHAR | 2 | Optional |
| LFBW | WT_WITHCD | WT_WITHCD | Withholding Tax Code | CHAR | 2 | Optional with mapping |
| STXH | TDOBJECT | TDOBJECT | Text object | CHAR | 10 | Conditional |
| STXH | TDNAME | TDNAME | Text Name | CHAR | 70 | Conditional |
| STXH | TDID | TDID | Text ID | CHAR | 4 | Conditional |
| STXH | TDSPRAS | TDSPRAS | Language Key | LANG | 1 | Conditional |
| STXL | TDOBJECT | TDOBJECT | Text object | CHAR | 10 | Conditional |
| STXL | TDNAME | TDNAME | Text name | CHAR | 70 | Conditional |
| STXL | TDID | TDID | Text ID | CHAR | 4 | Conditional |
| STXL | TDSPRAS | SPRAS | Language key | CHAR | 1 | Conditional |
| STXL | CLUSTD | CLUSTD | Data | CHAR | 7902 | Conditional |
Table: BUT100 - Role FLVN00- assignment to a Business Partner.
| BUT100 | PARTNER | BU_PARTNER | Business Partner Number | CHAR | 10 | Mandatory |
| BUT100 | RLTYP | BU_PARTNERROLE | BP Role | CHAR | 6 | Mandatory |
Data Cleansing
All data cleansing should take place in the data source system as defined in this document, unless system limitations prevent it.
If data cleansing is managed outside of the source system (e.g. Syniti Migrate, 3rd Party Vendor, DCT), the necessary documentation must be produced and appended to this deliverable for sign-off.
| ID | Criticality | Error Message/Report Description | Rule | Output | Source System |
|---|---|---|---|---|---|
| No legacy cleansing | Based on CNV-3007 relevancy rule and this CS relevancy rule | Relevant vendors vs excluded vendors | PF2/WP2 | ||
Conversion Process
The high-level process is represented by the diagram below:
Data Privacy and Sensitivity
Summarize Data Privacy and Sensitivity Requirements, if anyExtraction
Extract data from a source into Syniti. There are 2 possibilities:
- The data exists. Syniti connects to the source and loads the data into Syniti. There are 3 methods:
- Perform full data extraction from relevant tables in the source system(s).
- Perform extraction through the application layer.
- Only if Syniti cannot connect to the source, data is loaded to the repository from the provided source system extract/report.
The agreed Relevancy criteria is applied to the extracted records to identify the records that are applicable for the Target loads
Extraction Run Sheet
| Req # | Requirement Description | Team Responsible |
|---|---|---|
| 1 | Refresh Vendor general data / XREF in Syniti | Data |
| 2 | Refresh LFB1, LFBW, STXH, STXL tables via Syniti (Vendor company data) for all legacy systems | Data |
Selection Screen
If applicable, this section will give the details on any selection screen parameters, including the parameter type, that are required to be entered to ensure consistent data extracts.| Selection Ref Screen | Parameter Name | Selection Type | Requirement | Value to be entered/set |
|---|---|---|---|---|
| N/A | ||||
Data Collection Template (DCT)
Data Collection Template is required for enrichment purposes eg. legacy fields are missing data which is mandatory in target S4. The DCT fields are target values requiring no transformation.| Field Name | Field description | Rule |
| LFB1-LIFNR | Vendor number | |
| LFB1-BUKRS | Company code | |
| LFB1-FDGRV | Planning Group |
Extraction Dependencies
List the steps that need to occur before extraction can commence
| Item # | Step Description | Team Responsible |
|---|---|---|
| 1 | Ensure Syniti has the necessary connection and access to legacy servers | Data |
| 2 | Ensure that the necessary cleansing activities in legacy sources are complete (if any) | Data / Business |
| 3 | Ensure that create, change and deletion of master data is frozen or cut-off in legacy Production system | Legacy IT |
Transformation
The Target fields are mapped to the applicable Legacy field that will be its source, this is a 3-way activity involving the Business, Functional team and Data team. This identifies the transformation activity required to allow Syniti to make the data Target ready:
- Perform value mapping and data transformation rules.
- Legacy values are mapped to the to-be values (this could include a default value)
- Values are transformed according to the rules defined in Syniti
- Prepare target-ready data in the structure and format that is required for loading via prescribed Load Tool. This step also produces the load data ready for business to perform Pre-load Data Validation
Transformation Run Sheet
| Item # | Step Description | Team Responsible |
|---|---|---|
| 1 | LFA1 relevancy execution in Syniti | Data |
| 2 | LFB1 / LFBW / STXH/ STXL relevancy execution in Syniti | Data |
| 3 | Business partner FI Vendor execution in Syniti | Data |
Transformation Rules
Rule # | Source system | Source Table | Source Field | Source description | Target system | Target Table_Field | Target Table_Field | Target description | Transformation logic |
1 | PF2/WP2 | LFB1 | LIFNR | Vendor Number | S/4HANA | BCS002 | LIFNR | Vendor Number | Derive via legacy to BP Master Mapping |
2 | PF2/WP2 | LFB1 | BUKRS | Company Code | S/4HANA | BS001 | BUKRS | Company Code | Derive via Company Code mapping |
3 | PF2/WP2 | LFB1 | AKONT | Reconciliation Account | S/4HANA | LFB1 | AKONT | Reconciliation Account | Derive via GL account mapping |
4 | PF2/WP2 | LFB1 | ZUAWA | Sort Key | S/4HANA | LFB1 | ZUAWA | Sort Key | Derive via Sort key mapping (default mapping to 009) |
5 | PF2/WP2 | LFB1 | ZTERM | Payment Terms | S/4HANA | LFB1 | ZTERM | Payment Terms | Derive via Payment Terms mapping |
8 | PF2/WP2 | LFB1 | REPRF | Check Double Invoice | S/4HANA | LFB1 | REPRF | Check Double Invoice | Default Check ‘X’ |
9 | PF2/WP2 | LFB1 | ZWELS | Payment Methods | S/4HANA | LFB1 | ZWELS | Payment Methods | Derive via Payment Methods mapping |
10 | PF2/WP2 | LFB1 | TOGRR | Delivery Tolerance Group | S/4HANA | LFB1 | TOGRR | Delivery Tolerance Group | Derive via Tolerance Grp mapping |
14 | PF2/WP2 | LFB1 | ZAHLS | Block Key For Payment | S/4HANA | LFB1 | ZAHLS | Block Key for Payment | Derive via Payment block mapping |
18 | PF2/WP2 | LFB1 | FDGRV | Planning Group | S/4HANA | LFB1 | FDGRV | Planning Group | Derive via Planning Group mapping |
21 | PF2/WP2 | LFB1 | LNRZB | Account number of the alternative payee | S/4HANA | LFB1 | LNRZB | Account number of the alternative payee | Derive via legacy to BP Master Mapping |
28 | PF2/WP2 | LFB1 | HBKID | Short Key for a House Bank | S/4HANA | LFB1 | HBKID | Short Key for a House Bank | Derive via House bank mapping |
33 | PF2/WP2 | LFB1 | QSREC | RECIPIENT TYPE | S/4 HANA | LFB1 | QSREC | RECIPIENT TYPE | Derive via Recipient type mapping |
36 | PF2/WP2 | LFB1 | ALTKN | Previous Master Record Number | S/4HANA | LFB1 | ALTKN | Previous Master Record Number | Legacy vendor number LFB1-LIFNR |
39 | PF2/WP2 | LFB1 | UZAWE | Payment Method Supplement | S/4HANA | LFB1 | UZAWE | Payment Method Supplement | Derive via Payment Method Supplement mapping |
45 | PF2/WP2 | LFB1 | INTAD | Internet address of partner company clerk | S/4HANA | LFB1 | INTAD | Internet address of partner company clerk | To leave blank |
46 | PF2/WP2 | LFB1 | XLFZB | Indicator: Alternative payee using account number | S/4HANA | LFB1 | XLFZB | Indicator: Alternative payee using account number | Keep legacy value |
56 | PF2/WP2 | LFBW | LIFNR | Vendor Number | S/4HANA | BCS002 | LIFNR | Vendor Number | Derive via legacy to BP Master Mapping |
57 | PF2/WP2 | LFBW | BUKRS | Company Code | S/4HANA | BS001 | BUKRS | Company Code | Derive via Company Code mapping |
58 | PF2/WP2 | LFBW | WITHT | WITHHOLDING TAX TYPE | S/4HANA | LFBW | WITHT | WITHHOLDING TAX TYPE | Derive from Withholding tax mapping |
59 | PF2/WP2 | LFBW | WT_WITHCD | WITHHOLDING TAX CODE | S/4HANA | LFBW | WT_WITHCD | WITHHOLDING TAX CODE | Derive from Withholding tax mapping |
60 | PF2/WP2 | LFBW | WT_SUBJCT | SUBJECT TO WITHHOLDING TAX | S/4HANA | LFBW | WT_SUBJCT | SUBJECT TO WITHHOLDING TAX | Keep legacy value |
61 | PF2/WP2 | LFBW | QSREC | WITHHOLDING TAX TYPE OF RECIPIENT | S/4HANA | LFBW | QSREC | WITHHOLDING TAX TYPE OF RECIPIENT | Derive from Withholding tax recipient mapping |
62 | PF2/WP2 | LFBW | WT_WTSTCD | WITHHOLDING TAX ID | S/4HANA | LFBW | WT_WTSTCD | WITHHOLDING TAX ID | Keep legacy value |
63 | PF2/WP2 | LFBW | WT_EXNR | EXEMPTION NUMBER | S/4HANA | LFBW | WT_EXNR | EXEMPTION NUMBER | Keep legacy value |
64 | PF2/WP2 | LFBW | WT_EXRT | EXEMPTION % | S/4HANA | LFBW | WT_EXRT | EXEMPTION % | Keep legacy value |
65 | PF2/WP2 | LFBW | WT_WTEXRS | EXEMPTION REASON | S/4HANA | LFBW | WT_WTEXRS | EXEMPTION REASON | Keep legacy value |
| 66 | PF2/WP2 | LFBW | WT_EXDF | EXEMPTION FROM | S/4HANA | LFBW | WT_EXDF | EXEMPTION FROM | Keep legacy value |
| 67 | PF2/WP2 | LFBW | WT_EXDT | EXEMPTION TO | S/4HANA | LFBW | WT_EXDT | EXEMPTION TO | Keep legacy value |
| 68 | WP2/PF2 | STXH | TDOBJECT | Text object | S4 Hana | STXH | TDOBJECT | Text object | Keep legacy value = LFB1 |
| 69 | WP2/PF2 | STXH | TDNAME | Text Name | S4 Hana | STXH | TDNAME | Text Name | Derive via legacy to BP Master Mapping (leading zero within 10 chars) concatenate with company code mapping (4 chars) |
| 70 | WP2/PF2 | STXH | TDID | Text ID | S4 Hana | STXH | TDID | Text ID | Keep legacy value |
| 71 | WP2/PF2 | STXH | TDSPRAS | Language Key | S4 Hana | STXH | TDSPRAS | Language Key | Keep legacy value |
| 72 | WP2/PF2 | STXL | TDOBJECT | Text object | S4 Hana | STXH | TDOBJECT | Text object | Keep legacy value = LFB1 |
| 73 | WP2/PF2 | STXL | TDNAME | Text Name | S4 Hana | STXL | TDNAME | Text Name | Derive via legacy to BP Master Mapping (leading zero within 10 chars) concatenate with company code mapping (4 chars) |
| 74 | WP2/PF2 | STXL | TDID | Text ID | S4 Hana | STXL | TDID | Text ID | Keep legacy value |
| 75 | WP2/PF2 | STXL | TDSPRAS | Language Key | S4 Hana | STXL | TDSPRAS | Language Key | Keep legacy value |
| 76 | WP2/PF2 | STXL | CLUSTD | Data | S4 Hana | STXL | CLUSTD | Data | Keep legacy value |
1 | PF2/WP2 | N/A | N/A | N/A | S4HANA | BUT100 | PARTNER | Business Partner Number | Refer to XREF of Business Partner |
2 | PF2/WP2 | N/A | N/A | N/A | S4HANA | BUT100 | RLTYP | BP Role | Default to FLVN00 |
| 3 | PF2/WP2 | N/A | N/A | N/A | S4HANA | BUT100 | VALID_FROM | Validity Start of a BP Role | Default to 10101000000 (01.01.1900) |
| 4 | PF2/WP2 | N/A | N/A | N/A | S4HANA | BUT100 | VALID_TO | Validity End of a BP Role | Default to 99991231235959 (31.12.9999) |
List of Custom Target Reports for this object is maintained here: Conversion Specification - Custom Reports Register.
Transformation Mapping
Mapping Table Name | Description |
BP Master Mapping | Legacy to S4 Business Partner Vendor mapping |
Company Code Mapping | Legacy to S4 Company Code Mapping |
Payment Terms Mapping | Legacy to S4 Payment Terms Mapping |
Payment Method Mapping | Payment Method Mapping |
Tax Category Mapping | Legacy to S4 Tax Category Mapping |
GL Account Mapping | Legacy to S4 GL Account Mapping |
Sort Key Mapping | Legacy to S4 Sort Key Mapping |
Planning Group Mapping | Legacy to S4 Planning Group Mapping |
Withholding tax type / code Mapping | Legacy to S4 Withholding tax type / code Mapping |
Tolerance Group Mapping | Legacy to S4Tolerance Group Mapping |
Payment block Mapping | Legacy to S4Payment block Mapping |
Authorization Group Mapping | Legacy to S4Authorization Group Mapping |
Planning Group Mapping | Legacy to S4Planning Group Mapping |
| House bank mapping | Legacy to S4House bank mapping |
| Tolerance Group mapping | Legacy to S4Tolerance Group mapping |
| Payment Method Supplement mapping | Legacy to S4 Payment Method Supplement mapping |
Recipient type mapping | Legacy to S4 Recipient type mapping |
Withholding tax recipient mapping | Legacy to S4 Withholding tax recipient mapping |
Transformation Dependencies
List the steps that need to occur before transformation can commence| Item # | Step Description | Team Responsible |
|---|---|---|
1 | Extract PF2/WP2 source tables – LFB1, LFBW, STXH, STXL | Data |
2 | Ensure that Business Partner – General and COA GL accounts are loaded | Data |
3 | Ensure all vendor master data collection templates, deduplication and cleansing completeness and no errors | Data |
4 | Ensure that all required Configurations are in S/4HANA | Data |
5 | Ensure mappings are completed | Data |
Pre-Load Validation
Project Team
The following pre-load validations will be performed by the Project Team.Completeness
| Task | Action |
|---|---|
Verify count | Verify that the record count in the pre-load file is the same as the record count based on the approved records |
Accuracy
| Task | Action |
|---|---|
Data Accuracy | Data team to verify that all the data in the load table/file is accurate as per signed-off transformation rules contents |
Mapping Error Reports | Verify that all necessary error reports have been validated, and that errors have been addressed. |
Business
The following pre-load validations will be performed by the business.Completeness
| Task | Action |
|---|---|
Verify Count for External Vendor (not Key Input Supplier) | Verify that the record count in the pre-load file is the same as the record count based on the relevancy (including deduplication) results |
Verify Count for Intercompany Vendor | Verify that the record count in the pre-load file is the same as the record count based on the approved records (intercompany Vendors) |
Verify Relevancy Rules | Verify that the relevancy rules were correctly applied |
Accuracy
| Task | Action |
|---|---|
Verify Data Accuracy | Verify that all the data in the load table/file is accurate as per signed-off transformation rules and contents |
Review Error Reports | Verify that all necessary error reports have been validated, and that errors have been addressed. |
Verify Transformation Rules | Verify that the transformation rules are correct and have been carried out correctly |
Load
Loading will be done through migration cockpit and therefore, data from the transformation export view to be exported into the load file format.
export views to be prepared based on the field list from the load template attached.
The load process includes:
- Execute the automated data load into target system using load tool or product the load file if the load must be done manually
- Once the data is loaded to the target system, it will be extracted and prepared for Post Load Data Validation
Load Run Sheet
Item | Step description | Team responsible |
1 | Ensure the load tools are transported into the correct tool instance. | Data team |
2 | Ensure all required mappings are submitted and complete | Data team |
3 | Ensure Pre-load sign-offs are obtained. | Data team |
4 | Execute Upload tool | Data team |
5 | Generate the post load reports in tool. | Data team |
6 | Log errors as defects, if any and address resolutions. Close defects. | Data team |
7 | Resolve defects by reupload and re-generate post load reports if necessary. | Data team |
8 | Business to validate the post load files as part of post-load validation, raise data defects or provide the post-load sign-off. | Business |
9 | Repeat steps 5 to 7 if necessary. | Data team |
Load Phase and Dependencies
Identify the phase as to “when” the load for this object will occur. <Pre-Cutover, Cutover, Post Cutover> and list the steps that need to occur before the load can commence
Configuration
List the Configurations required before loading can commence
| Item # | Configuration Item |
|---|---|
1 | Obtain the approved upload USER ID’s to be used (e.g. Firefighter ID) |
2 | SAP USER profile (SU3) Date and Decimal Notation Formats are in sync with the load format |
3 | Company Code Configuration |
4 | Payment Terms Configuration |
5 | Payment Method Configuration |
6 | Reconciliation Account Configuration |
7 | Withholding Tax Types Configuration |
8 | Sort Key configuration |
9 | Planning Group configuration |
10 | Tolerance Group configuration |
11 | Payment block configuration |
12 | Authorization Group configuration |
13 | Planning Group configuration |
14 | Accounting Clerk configuration |
15 | House bank configuration |
16 | Tolerance Group configuration |
17 | Payment Method Supplement configuration |
18 | Recipient type configuration |
Conversion Objects
| Object # | Preceding Object Conversion Approach |
|---|---|
3007 | Business Partner – General |
1067 | GL Account Operational CoA (incl. secondary CE) |
Error Handling
The table below depicts some possible system errors for this data object during data load. All data load error is to be logged as defect and managed within the Defect Management
| Error Type | Error Description | Action Taken |
|---|---|---|
Configuration | <configuration> is not valid/missing | If it is a missing configuration item then engage Functional team to expedite and fix the error in the system. |
Invalid Data | <parameter> is not valid. | The parameter entry needs to be reviewed (ex. invalid payment terms). If it is an invalid data, business needs to review and correct the source of the data either in PF2/WP2. |
Technical Setup | Interface / Connection issue within target system’s landscape | N/A – the data will be loaded directly to S/4HANA environment |
Post-Load Validation
Project Team
The following post-load validations will be performed by the Project Team.Completeness
| Task | Action |
|---|---|
Verify Count for External Vendor | Verify that the record count in the post-load file is the same as the record count based on the relevancy (including deduplication) results |
Verify Count for Intercompany Vendor | Verify that the record count in the post-load file is the same as the record count based on the approved records (intercompany Vendors) |
Verify Count for Key Input Suppliers | Verify that the record count in the post-load file for Key Input supplier types are the same as the record count based on the approved records for Key Input Suppliers |
Accuracy
| Task | Action |
|---|---|
Data Accuracy | Data team to verify that all the data in the load table/file is accurate as per signed-off transformation rules and contents |
Error Reports | Verify that all necessary error reports have been validated, and that errors have been addressed. |
Business
The following post-load validations will be performed by the business.Completeness
| Task | Action |
|---|---|
Verify Count for External Vendor | Verify that the record count in the post-load file is the same as the record count based on the relevancy (including deduplication) results |
Verify Count for Intercompany Vendor | Verify that the record count in the post-load file is the same as the record count based on the approved records (intercompany Vendors) |
Verify Count for Key Input Suppliers | Verify that the record count in the pre-load file for Key Input supplier types are the same as the record count based on the approved records for Key Input Suppliers |
Validate Loaded Data | Validate, as per the loads files signed-off, that all records were created |
Accuracy
| Task | Action |
|---|---|
Verify Data Accuracy | Data team to verify that all the data in the load table/file is accurate as per signed-off transformation rules and contents |
Review Error Reports | Verify that all necessary error reports have been validated, and that errors have been addressed. |
Validate Loaded Data | Validate, as per the loads files signed-off, that all records were created |
Key Assumptions
- Master Data Standard is up to date as on the date of documenting this conversion approach and data load.
- BP Vendor General is in scope based on data design and any exception requested by business.
Any additional key assumptions.
See also
Insert links and references to other documents which are relevant when trying to understand this decision and its implications. Other decisions are often impacted, so it's good to list them here with links. Attachments are also possible but dangerous as they are static documents and not updated by their authors.