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Decision Trees

Applies to: All subscriptions

Purpose

Collect every diagnostic tree in one place so a support team can print them, put them in a runbook, or link an alert directly to the relevant one. Each tree also appears in context on its own page, with the detailed paths.

Audience

First-line and second-line support. Whoever writes the runbooks.

Prerequisites

Reference

Tree 0 — triage

  Problem reported
        |
        v
  Is anyone able to use the system at all?
        |
        +-- Nobody -------> Tree 6: Performance and Availability
        |
        +-- One person ---> Tree 5: Login and Access
        |
        +-- Yes, but ...
              |
              +-- documents not arriving -----> Tree 3: Ingest
              +-- will not register ----------> Tree 1: IRN
              +-- e-Way Bill problem ---------> Tree 2: e-Way Bill
              +-- ERP missing outcomes -------> Tree 4: Write-back
              +-- everything slow ------------> Tree 6: Performance
              +-- something missing ----------> the three gates below

The three gates — "something is missing"

  What is the user actually seeing?
        |
        +-- The whole module is ABSENT --------> Feature flag
        |                                        -> enable for that registration
        |
        +-- Screen present, controls GREYED ---> Role permission
        |                                        -> change the role
        |
        +-- Screen loads, NO DATA -------------> Registration access
                                                 -> grant access

One question — "is it missing, greyed, or empty?" — usually ends the investigation.

Tree 1 — a document will not register

  No reference number
        |
        v
  Visible in the workbench?
        |
        +-- No --> In the Correction Cockpit?
        |            +-- Yes --> QUARANTINED: read every field message
        |            +-- No ---> Query status by number
        |                          +-- Not found --> never arrived: Tree 3
        |                          +-- Found ------> registration access
        |
        +-- Yes --> Status?
                      +-- Awaiting generation --> nobody generated it.
                      |                            CHECK THE REPORTING WINDOW
                      +-- Failed --> numbered error?
                      |                +-- Yes --> government rejection:
                      |                |            look up who fixes it
                      |                +-- No ---> provider: run connection test
                      +-- Cancelled ----------> number consumed permanently
                      +-- Registered ---------> it worked; check the ERP

Full detail: IRN Failures.

Tree 2 — e-Way Bill

  An e-Way Bill problem
        |
        +-- Cannot generate ----------> source registered? transport data?
        |                               distance? connection? capability?
        +-- Goods stopped ------------> PART-B almost always
        +-- Expired ------------------> extend if in window; otherwise statutory
        +-- Extension refused --------> outside the extension window
        +-- Cannot cancel ------------> window closed, or already cancelled
        +-- Consolidated unavailable -> provider capability, not a fault

Full detail: e-Way Bill Failures.

Tree 3 — ingest

  Document missing or wrong
        |
        v
  Does the ERP believe it sent it?
        |
        +-- No ---> ERP side: trigger, criteria, job
        |
        +-- Yes --> response received?
                      +-- none / timeout --> QUERY STATUS BEFORE RESENDING
                      +-- 401 -------------> credential
                      +-- 403 -------------> credential SCOPE, not user role
                      +-- 409 -------------> duplicate; check the numbering series
                      +-- 422 -------------> validation; one document or all?
                      +-- 201 -------------> it is here: quarantined? not visible?
                                              values wrong? -> mapping

Full detail: Ingest Failures.

Tree 4 — write-back

  ERP missing outcomes
        |
        v
  Write-back enabled?
        +-- No ---> that is the answer. NOT retrospective
        |
        +-- Yes -> subscription exists?
                     +-- No ---> configure one
                     +-- Yes -> events being produced?
                                  +-- No ---> are the documents registered?
                                  +-- Yes -> backlog AGE rising?
                                               +-- Yes --> consumer or endpoint
                                               +-- No ---> delivered but discarded:
                                                            acknowledged before
                                                            committing

Full detail: Write-back Failures.

Tree 5 — login and access

  Access problem
        |
        v
  Can they sign in?
        +-- No --> one person or several?
        |            +-- Several --> CHECK MAIL FIRST
        |            +-- One ------> account state, password, lockout
        |
        +-- Yes -> the three gates above

Full detail: Login and Access Failures.

Tree 6 — performance and availability

  Slow or down
        |
        +-- No response --> refused: proxy or DNS
        |                   502: proxy cannot reach the API
        |                   504: timeout too short (CHECK STATUS BEFORE RETRY)
        |                   certificate: expired or incomplete chain
        |
        +-- Responds ----> everything, or one thing?
                             +-- Everything --> app high / db low --> app tier
                             |                  app low / db high --> MAINTENANCE FIRST
                             |                  both high --------> volume growth
                             |                  both low ---------> WAITING ON EXTERNAL
                             |
                             +-- One thing ---> government: provider
                                                uploads: worker or queue
                                                printing: rendering memory
                                                one report: data volume

Full detail: Performance and Availability.

Validation

Check Pass condition
Trees are accessible where they are needed Printed, in the runbook, or linked from alerts
First-line can follow them unaided Tested with someone who has not read the detail pages
Alerts link to the right tree Each alert names its tree
Trees are reviewed Every escalation is checked for whether a tree should have caught it

Troubleshooting

Symptom Cause Action
A tree leads nowhere useful It covers the common case, not this one Escalate with what you tried, and propose the addition
First-line skips the trees Not accessible at the moment of need Put them in the runbook and link them from alerts
Two trees seem to apply The symptom is ambiguous Start at Tree 0; it disambiguates
A tree is out of date The product changed Trees are maintained with the pages they summarise; report the divergence