MFS BlackBox

Material Flow System / EWM telegram sequence, handshake, heartbeat, warehouse-task state and PLC release auditor with incident clustering and minimal reproduction

Content reviewed September 26, 2026

Engine: MFS_BLACKBOX
Domain: Warehouse Automation
Version: 1.3.0
Target releases: S4H_2022, S4H_2023, S4HANA_CLOUD_2402, S4HANA_CLOUD_2408
Accepted formats: JSON, CSV, XLSX

Input contract

MFS telegram log: CSV/TSV/pipe log with a header row (type, hu_id, cp, to_cp, seq_no, sender_plc, receiver_plc, status, time_sec/timestamp, wt_id, plc_release; EDGE,<from>,<to> rows declare conveyor topology), the same table as the first worksheet of an XLSX workbook, or JSON {'telegrams': [...], 'conveyor_edges': [[from, to]], 'configuration': {ack_timeout_seconds, max_retries, heartbeat_timeout_seconds, completion_timeout_seconds, recurrence_threshold}}. Inline payloads are bounded by the service payload limit; delimited logs of any size (multi-GB) are streamed through POST /api/v1/analyze/stream and processed line by line with bounded memory.

Required input

At least one telegram with a 'type'

Telegram families: LIFE / HEARTBEAT (heartbeat timeout), WT / WTCR / TO (warehouse task created, destination to_cp), WTCO / CONF / DONE (completion, confirmed location cp). XLSX: first worksheet, max 200,000 rows, read through the hardened ZIP reader and defusedxml. No simulator adapter: the minimal reproduction is exported as a JSON regression fixture instead.

Finding codes

Finding codes (11)

MFS_FIRST_CAUSAL_DIVERGENCEDefault severity: CriticalCategory: CAUSAL_DIAGNOSTICS
First causal divergence in the incident timeline
Remediation: Start the root-cause analysis at the referenced telegram; later anomalies are likely consequences.
MFS_HEARTBEAT_TIMEOUTDefault severity: CriticalCategory: TELEGRAM_HANDSHAKE
LIFE / heartbeat telegram gap exceeds the timeout
Remediation: Check the PLC connection of the channel, the life-telegram interval of the PLC interface and the network; resynchronise the channel after the interruption and check for telegrams lost in the gap.
MFS_IMPOSSIBLE_TOPOLOGY_JUMPDefault severity: CriticalCategory: CONVEYOR_TOPOLOGY
HU moved between non-adjacent conveyor points
Remediation: Verify the conveyor segment / communication point definitions against the physical layout and check for missed scanner reads between the two points.
MFS_MISSING_ACK_TIMEOUTDefault severity: CriticalCategory: TELEGRAM_HANDSHAKE
Telegram not acknowledged within timeout
Remediation: Check PLC connectivity and the channel's ACK timeout; unacknowledged moves leave warehouse tasks open.
MFS_WRONG_CONFIRMATIONDefault severity: CriticalCategory: WAREHOUSE_TASK_STATE
Warehouse task confirmed for a wrong HU / destination or twice
Remediation: Correct the HU position in EWM (/SCWM/MON), check the PLC's destination / HU mapping for the task and the confirmation telegram layout.
MFS_CORRUPTED_TELEGRAMDefault severity: MajorCategory: DATA_INTEGRITY
Malformed telegram record
Remediation: Check the PLC / MFS telegram structure definition (/SCWM/MFS telegram structures) and the log export; corrupted records were excluded from the reconstruction.
MFS_DUPLICATE_TELEGRAM_SENDDefault severity: MajorCategory: TELEGRAM_RETRY_STORM
Duplicate telegram retransmission (retry storm)
Remediation: Investigate missing / late ACKs that trigger retransmission; tune the resend interval and max retries in the channel configuration.
MFS_MISSING_COMPLETIONDefault severity: MajorCategory: WAREHOUSE_TASK_STATE
Warehouse task never confirmed
Remediation: Locate the HU, check whether the PLC executed the transport and confirm or cancel the warehouse task in EWM (/SCWM/MON); check the PLC's completion telegram for the destination.
MFS_OUT_OF_ORDER_SEQUENCEDefault severity: MajorCategory: TELEGRAM_ORDERING
Telegram sequence out of order or with gaps
Remediation: Check the communication channel's sequence number handling and resend buffer (/SCWM/MFS_CP_CHANNEL monitoring); lost telegrams must be resynchronised with the PLC.
MFS_PLC_RELEASE_REGRESSIONDefault severity: MajorCategory: PLC_RELEASE_COMPARISON
Anomaly rate increased after a PLC software release change
Remediation: Compare the telegram behaviour of both PLC releases with the PLC vendor and re-test the affected scenarios on a simulator before rolling the release out further (the result is a correlation, not a proof).
MFS_RECURRING_INCIDENT_PATTERNDefault severity: MajorCategory: INCIDENT_CLUSTERING
Incident fingerprint recurs across HUs / occurrences
Remediation: Treat the fingerprint as one systematic problem (topology definition, channel, PLC program) and fix the shared cause; track the fingerprint in later logs to confirm the fix.

Input validation codes (5)

MFS_ARCHIVE_REJECTEDDefault severity: MajorCategory: INPUT_VALIDATION
Archive rejected by ingestion safety limits
Remediation: The archive exceeded the 100:1 expansion ratio, 500 MB total size, entry-count or 2-level nesting limit, or contained path traversal / encrypted members. Upload a flat, unencrypted archive of the export files. No verdict was produced. Re-export the artifact in one of the formats accepted by MFS BlackBox (JSON, CSV, XLSX) and re-run the analysis.
MFS_INVALID_INPUTDefault severity: MajorCategory: INPUT_VALIDATION
Artifact does not match the engine input contract
Remediation: Provide the artifact type documented for this engine; unrelated or structurally invalid documents are rejected. No verdict was produced. Re-export the artifact in one of the formats accepted by MFS BlackBox (JSON, CSV, XLSX) and re-run the analysis.
MFS_PARSE_ERRORDefault severity: MajorCategory: INPUT_VALIDATION
Artifact could not be parsed
Remediation: Fix the syntax error at the reported line/column (or re-export the file unmodified from SAP). No verdict was produced. Re-export the artifact in one of the formats accepted by MFS BlackBox (JSON, CSV, XLSX) and re-run the analysis.
MFS_PAYLOAD_TOO_LARGEDefault severity: MajorCategory: INPUT_VALIDATION
Artifact exceeds the size limit
Remediation: Split the export (e.g. per package, company code or date range) so each upload stays under the service payload limit. No verdict was produced. Re-export the artifact in one of the formats accepted by MFS BlackBox (JSON, CSV, XLSX) and re-run the analysis.
MFS_INSUFFICIENT_INPUTDefault severity: InfoCategory: INPUT_VALIDATION
Required input missing
Remediation: Supply every input the engine's contract marks as required (see the engine catalog entry). No verdict was produced. Re-export the artifact in one of the formats accepted by MFS BlackBox (JSON, CSV, XLSX) and re-run the analysis.

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