docs(workflow): ADR-0016 + demo note for diploma-eligibility DMN (S-13, refs #14)

Record the DMN-as-businessRuleTask decision (from proposal #100) and add the S-13
demo walkthrough showing a foreign diploma routing through CBGV-advies.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

docs/architecture/adr-0016-diploma-eligibility-dmn.md

@@ -0,0 +1,66 @@
+# ADR-0016: Diploma eligibility is a DMN evaluated inline as a BPMN businessRuleTask
+
+- **Status:** Accepted
+- **Date:** 2026-07-17
+- **Deciders:** Respellion engineering
+- **Relates to:** S-13 (#14); proposal #100. Builds on ADR-0009 (external-task worker / Workflow
+  Client), ADR-0014/0015 (the boundary-event and routing constructs on the registratie process).
+
+## Context
+
+S-13 adds flow 4: a foreign diploma must get an extra CBGV-advies assessment before beoordeling
+(PRD §5). The eligibility decision — domestic goes straight to beoordeling, foreign routes through
+CBGV-advies — needs a home. The Flowable REST app bundles a DMN engine, and the same
+`repository/deployments` machinery that deploys `registratie.bpmn` can deploy a `.dmn`. §8.2 makes
+the Workflow Client the only code that talks to Flowable; the PRD frames the workflow as "BPMN + DMN
+governing the registration workflow" (Flowable as a peer orchestration module).
+
+The issue's wording ("a DMN decision table evaluated by the Domain Service via Workflow Client")
+suggests the domain reaches into Flowable's DMN API to evaluate the decision and feeds the result
+back. That is one option; it is not the only one, and it is not the cleanest.
+
+## Decision
+
+**The diploma-eligibility DMN is deployed to Flowable and evaluated inline by the registratie process
+as a `businessRuleTask`; an exclusive gateway routes on its output. The domain's only new job is to
+carry the diploma origin and pass it into the process as a start variable.**
+
+- **The decision lives in the workflow.** `workflows/diploma-eligibility.dmn` maps `diplomaOrigin`
+  → `route` (`Buitenlands` ⇒ `CBGV_ADVIES`, otherwise `DIRECT`). A `businessRuleTask`
+  (`flowable:type="dmn"`, `decisionTableReferenceKey=diploma-eligibility`) runs it between
+  `OpenZaakAanmaken` and `Beoordelen`, and an exclusive gateway sends `CBGV_ADVIES` through a new
+  `CBGVAdvies` user task before `Beoordelen`, `DIRECT` straight there.
+- **The domain carries the input, not the decision.** The `Registration` aggregate gains a
+  `DiplomaOrigin` (Binnenlands/Buitenlands); `SubmitRegistration` passes it to
+  `StartRegistrationProcessAsync`, which sets it as the `diplomaOrigin` start variable. The domain
+  never evaluates the DMN and never learns the route — that is the process's concern.
+- **Deployed like the BPMN.** The DMN is version-controlled in `workflows/` and deployed to the DMN
+  engine by the same `flowable-init` step (via `dmn-api/dmn-repository/deployments`), staged into the
+  `fl-bpmn` volume alongside the BPMN.
+
+## Consequences
+
+**Positive**
+
+- The eligibility rule is a first-class, inspectable workflow artefact (matching the PRD's BPMN+DMN
+  framing); business users can read/adjust the decision table without touching domain code.
+- §8.2 stays clean: the Workflow Client remains the only code talking to Flowable, and the decision
+  runs inside the process the client already started — no domain→Flowable round-trip for a decision.
+- The domain change is minimal and additive: one value on the aggregate, one start variable.
+
+**Negative / costs**
+
+- Deviates from #14's literal "evaluated by the Domain Service via Workflow Client" wording (noted on
+  the issue). The outcome — DMN decides eligibility, foreign diplomas get the CBGV step — is unchanged.
+- The DMN and its `businessRuleTask` wiring are validated live (verify-domain drives a foreign
+  registration through CBGV-advies and a domestic one straight to beoordeling, exercising both
+  branches), not in unit tests — consistent with ADR-0009/0014/0015. The domain unit/acceptance tests
+  cover only that the origin is carried into the process.
+
+## Alternatives considered
+
+- **Domain evaluates the DMN via the Workflow Client** (the issue's wording). Rejected: it couples
+  the domain to Flowable for a decision and splits the routing across two places (domain computes,
+  BPMN branches), for no benefit over letting the engine that owns the process own the decision.
+- **Eligibility rules in domain C#.** Rejected: it moves a governable business decision out of the
+  DMN the PRD calls for, and hard-codes what the reference app is meant to demonstrate as data.

docs/demo-script.md

@@ -343,3 +343,42 @@ candidate group behandelaar → teamlead (§8.2).
 > Both branches (escalate after 14 days; no-op when completed in time) are covered by the
 > `Een beoordeling escaleren` acceptance scenarios and the Workflow Client unit tests; the timer firing
 > and reassignment are asserted live by the verify-domain check.
+
+## S-13 — Diploma-eligibility: foreign diplomas route through CBGV-advies (#14, ADR-0016)
+
+A registration's diploma origin decides its route. A DMN `businessRuleTask` in the registratie
+process evaluates the `diploma-eligibility` decision on the `diplomaOrigin` start variable: a
+**foreign** (Buitenlands) diploma is routed through an extra **CBGV-advies** user task before
+beoordeling; a **domestic** (Binnenlands) one goes straight to beoordeling. The decision lives in the
+DMN, not in code — a beheerder can read and adjust the decision table directly.
+
+The self-service portal's eIDAS→foreign wiring is a later slice; for now the origin is submitted to
+the domain directly, so the demo drives it through the domain endpoint:
+
+```bash
+# 1. Submit a foreign-diploma registration to the domain (note the returned Location/reference):
+DOM=http://localhost:8080   # domain service
+curl -s -i -X POST "$DOM/registrations" -H 'Content-Type: application/json' \
+  -d '{"bsn":"123456782","diplomaOrigin":"Buitenlands"}' | grep -i '^location:'
+#
+# 2. Once the zaak is opened, the process parks at the CBGV-advies task (NOT Beoordelen). In Flowable:
+FL=http://localhost:8090/flowable-rest/service
+curl -s -u rest-admin:test -X POST "$FL/query/tasks" -H 'Content-Type: application/json' \
+  -d '{"processDefinitionKey":"registratie","taskDefinitionKey":"CBGVAdvies"}' | python3 -m json.tool
+#
+# 3. Complete the CBGV-advies task; the case then advances to the regular Beoordelen task:
+TID=$(curl -s -u rest-admin:test -X POST "$FL/query/tasks" -H 'Content-Type: application/json' \
+  -d '{"processDefinitionKey":"registratie","taskDefinitionKey":"CBGVAdvies"}' \
+  | python3 -c 'import sys,json;print(json.load(sys.stdin)["data"][0]["id"])')
+curl -s -u rest-admin:test -X POST "$FL/runtime/tasks/$TID" \
+  -H 'Content-Type: application/json' -d '{"action":"complete"}'
+# A domestic submission (default, or "Binnenlands") skips CBGV-advies and parks straight at Beoordelen.
+```
+
+**The path:** domain sets the `diplomaOrigin` start variable → registratie process DMN
+`businessRuleTask` sets `route` → exclusive gateway → foreign: `CBGVAdvies` user task → `Beoordelen`;
+domestic: `Beoordelen` directly (§8.2, ADR-0016).
+
+> The domestic/foreign paths are covered by the `Een diploma op herkomst routeren` acceptance
+> scenarios and unit tests (the origin is carried into the process); the DMN decision and the
+> foreign→CBGV routing are asserted live by the verify-domain check.

infra/docker-compose.yml

@@ -259,7 +259,7 @@ services:
   flowable-init:
     image: docker.io/curlimages/curl:latest
     restart: "no"
-    # registratie.bpmn is streamed into this external volume by infra/seed-config.sh.
+    # registratie.bpmn + diploma-eligibility.dmn are streamed into this external volume by infra/seed-config.sh.
     volumes:
       - fl-bpmn:/work:ro
     command:
@@ -267,7 +267,15 @@ services:
       - -c
       - |
         base=http://flowable-rest:8080/flowable-rest/service/repository/deployments
+        dmnbase=http://flowable-rest:8080/flowable-rest/dmn-api/dmn-repository/deployments
         until curl -sf -u rest-admin:test "$$base" >/dev/null 2>&1; do echo "waiting for flowable-rest..."; sleep 3; done
+        # Deploy the diploma-eligibility DMN to the DMN engine so the registratie process's
+        # businessRuleTask can resolve it by key (S-13, ADR-0016).
+        if curl -s -u rest-admin:test "$$dmnbase?name=diploma-eligibility" | grep -q '"name":"diploma-eligibility"'; then
+          echo "diploma-eligibility already deployed; skip"
+        else
+          curl -sf -u rest-admin:test -F 'file=@/work/diploma-eligibility.dmn;filename=diploma-eligibility.dmn' "$$dmnbase" >/dev/null && echo "deployed diploma-eligibility"
+        fi
         if curl -s -u rest-admin:test "$$base?name=registratie" | grep -q '"name":"registratie"'; then
           echo "registratie already deployed; skip"
         else

infra/flowable/docker-compose.yml

@@ -35,12 +35,12 @@ services:
         condition: service_healthy
     networks: [cg]
 
-  # Deploys workflows/registratie.bpmn via the REST API once flowable-rest is up.
+  # Deploys workflows/registratie.bpmn + diploma-eligibility.dmn via the REST API once flowable-rest is up.
-  # Idempotent: skips if a deployment named "registratie" already exists.
+  # Idempotent: skips each if a deployment of that name already exists.
   flowable-init:
     image: docker.io/curlimages/curl:latest
     restart: "no"
-    # registratie.bpmn is streamed into this external volume by infra/seed-config.sh.
+    # registratie.bpmn + diploma-eligibility.dmn are streamed into this external volume by infra/seed-config.sh.
     volumes:
       - fl-bpmn:/work:ro
     command:
@@ -48,7 +48,15 @@ services:
       - -c
       - |
         base=http://flowable-rest:8080/flowable-rest/service/repository/deployments
+        dmnbase=http://flowable-rest:8080/flowable-rest/dmn-api/dmn-repository/deployments
         until curl -sf -u rest-admin:test "$$base" >/dev/null 2>&1; do echo "waiting for flowable-rest..."; sleep 3; done
+        # Deploy the diploma-eligibility DMN to the DMN engine so the registratie process's
+        # businessRuleTask can resolve it by key (S-13, ADR-0016).
+        if curl -s -u rest-admin:test "$$dmnbase?name=diploma-eligibility" | grep -q '"name":"diploma-eligibility"'; then
+          echo "diploma-eligibility already deployed; skip"
+        else
+          curl -sf -u rest-admin:test -F 'file=@/work/diploma-eligibility.dmn;filename=diploma-eligibility.dmn' "$$dmnbase" >/dev/null && echo "deployed diploma-eligibility"
+        fi
         if curl -s -u rest-admin:test "$$base?name=registratie" | grep -q '"name":"registratie"'; then
           echo "registratie already deployed; skip"
         else

infra/run-domain-check.sh

@@ -158,6 +158,49 @@ done
 [ -n "$gone" ] || { echo "FAIL — Beoordelen task for $reg_id2 still active after withdrawal" >&2; docker logs "$dom" 2>&1 | tail -15 >&2; exit 1; }
 echo "OK — withdrawal cancelled the Beoordelen task; the registratie process ended (ingetrokken)"
 
+# ── S-13: diploma-eligibility routing. A registration with a FOREIGN diploma must route through the
+# extra CBGVAdvies user task before Beoordelen (the DMN businessRuleTask sets route=CBGV_ADVIES and the
+# gateway branches, ADR-0016). The domestic DIRECT path is already proven by the first registration
+# above, which parked straight at Beoordelen. ──────────────────────────────────────────────────────
+cbgv_query='{"processDefinitionKey":"registratie","taskDefinitionKey":"CBGVAdvies","includeProcessVariables":true}'
+echo ">> submitting a registration with a foreign diploma"
+locf="$(docker run --rm --network "$net" curlimages/curl:latest \
+  -fsS -D - -o /dev/null -X POST "http://$dom_ip:8080/registrations" \
+  -H 'Content-Type: application/json' -d '{"bsn":"123456782","diplomaOrigin":"Buitenlands"}' \
+  | sed -n 's/\r$//; s/^[Ll]ocation: //p' | head -1)"
+[ -n "$locf" ] || { echo "FAIL — foreign POST /registrations returned no Location" >&2; exit 1; }
+reg_idf="${locf##*/}"
+echo ">> foreign registration $reg_idf"
+
+echo ">> polling Flowable for its CBGV-advies task (foreign diplomas route here first)"
+cbgv_task=""
+for _ in $(seq 1 30); do
+  resp="$(flcurl -X POST "$fl_base/query/tasks" -H 'Content-Type: application/json' -d "$cbgv_query" 2>/dev/null || true)"
+  cbgv_task="$(printf '%s' "$resp" | task_for_reg "$reg_idf")"
+  [ -n "$cbgv_task" ] && break
+  sleep 2
+done
+[ -n "$cbgv_task" ] || { echo "FAIL — no CBGVAdvies task appeared for the foreign registration $reg_idf" >&2; docker logs "$dom" 2>&1 | tail -15 >&2; exit 1; }
+echo ">> CBGVAdvies task $cbgv_task is waiting"
+
+echo ">> asserting it has NOT reached Beoordelen yet (still awaiting CBGV-advies)"
+resp="$(flcurl -X POST "$fl_base/query/tasks" -H 'Content-Type: application/json' -d "$query")"
+early="$(printf '%s' "$resp" | task_for_reg "$reg_idf")"
+[ -z "$early" ] || { echo "FAIL — foreign registration reached Beoordelen ($early) before CBGV-advies" >&2; exit 1; }
+
+echo ">> completing the CBGV-advies task"
+flcurl -X POST "$fl_base/runtime/tasks/$cbgv_task" -H 'Content-Type: application/json' -d '{"action":"complete"}' >/dev/null
+
+echo ">> asserting it now advances to Beoordelen"
+onward=""
+for _ in $(seq 1 15); do
+  resp="$(flcurl -X POST "$fl_base/query/tasks" -H 'Content-Type: application/json' -d "$query" 2>/dev/null || true)"
+  [ -n "$(printf '%s' "$resp" | task_for_reg "$reg_idf")" ] && { onward=1; break; }
+  sleep 2
+done
+[ -n "$onward" ] || { echo "FAIL — foreign registration did not reach Beoordelen after CBGV-advies" >&2; exit 1; }
+echo "OK — foreign diploma routed through CBGV-advies, then on to Beoordelen (DMN + gateway)"
+
 # ── S-14: escalation. A third registration parks at Beoordelen. We fire its 14-day boundary timer
 # early via Flowable's management API (the timer job is moved to executable and run), which routes a
 # parallel token to the BeoordelingEscaleren external task. The domain's escalation worker acquires

infra/seed-config.sh

@@ -40,7 +40,7 @@ for key in "$@"; do
     oz) populate rr-oz-config "$here/openzaak/setup_configuration/." ;;
     nrc) populate rr-nrc-config "$here/opennotificaties/setup_configuration/." ;;
     kc) populate rr-kc-realms "$here/keycloak/realms/." ;;
-    fl) populate rr-fl-bpmn  "$here/../workflows/registratie.bpmn" ;;
+    fl) populate rr-fl-bpmn  "$here/../workflows/." ;;  # registratie.bpmn + diploma-eligibility.dmn
     *)  echo "unknown seed key: $key" >&2; exit 2 ;;
   esac
 done

services/domain/Big.Api/Program.cs

@@ -48,7 +48,12 @@ app.MapGet("/health", () => "Healthy");
 // a location to read the registration's progress (ADR-0009, eventual consistency).
 app.MapPost("/registrations", async (SubmitRegistrationRequest body, SubmitRegistration submit, CancellationToken ct) =>
 {
-    var id = await submit.HandleAsync(new SubmitRegistrationCommand(body.Bsn), ct);
+    // Diploma origin defaults to domestic; a foreign (eIDAS) submission passes "Buitenlands" so the
+    // workflow's DMN routes it through CBGV-advies (S-13). An unknown value is a bad request.
+    if (!Enum.TryParse<DiplomaOrigin>(body.DiplomaOrigin, ignoreCase: true, out var origin) && body.DiplomaOrigin is not null)
+        return Results.BadRequest(new { error = $"Unknown diplomaOrigin '{body.DiplomaOrigin}'. Expected 'Binnenlands' or 'Buitenlands'." });
+
+    var id = await submit.HandleAsync(new SubmitRegistrationCommand(body.Bsn, origin), ct);
     return Results.Accepted($"/registrations/{id}", new RegistrationResponse(id.ToString(), RegistrationStatus.Ingediend.ToString(), null));
 });
 
@@ -117,7 +122,7 @@ app.MapGet("/registrations/{id}", async (string id, IRegistrationStore store, Ca
 
 await app.RunAsync();
 
-public sealed record SubmitRegistrationRequest(string Bsn);
+public sealed record SubmitRegistrationRequest(string Bsn, string? DiplomaOrigin = null);
 
 public sealed record DecideRequest(string Besluit);
 

services/domain/Big.Application/Ports.cs

@@ -11,10 +11,12 @@ public interface IWorkflowClient
 {
     /// <summary>
     /// Start one <c>registratie</c> process instance for the given registration, carrying the
-    /// registration id so the <c>OpenZaakAanmaken</c> external task can be correlated back to its
+    /// registration id (so the <c>OpenZaakAanmaken</c> external task can be correlated back to its
-    /// aggregate. Returns the process instance id.
+    /// aggregate) and the diploma origin (so the workflow's DMN can route foreign diplomas through
+    /// CBGV-advies, S-13). Returns the process instance id.
     /// </summary>
-    Task<string> StartRegistrationProcessAsync(RegistrationId registrationId, CancellationToken ct = default);
+    Task<string> StartRegistrationProcessAsync(
+        RegistrationId registrationId, DiplomaOrigin diplomaOrigin, CancellationToken ct = default);
 
     /// <summary>
     /// Cancel a running <c>registratie</c> process on withdrawal (S-11): correlate the

services/domain/Big.Application/SubmitRegistration.cs

@@ -2,8 +2,10 @@ using Big.Domain;
 
 namespace Big.Application;
 
-/// <summary>A zorgprofessional's request to register, in domain language. No ZGW concepts.</summary>
+/// <summary>A zorgprofessional's request to register, in domain language. No ZGW concepts. The
-public sealed record SubmitRegistrationCommand(string Bsn);
+/// diploma origin defaults to domestic (the DigiD path); a foreign (eIDAS) submission sets it to
+/// <see cref="DiplomaOrigin.Buitenlands"/> so the workflow's DMN routes it through CBGV-advies (S-13).</summary>
+public sealed record SubmitRegistrationCommand(string Bsn, DiplomaOrigin DiplomaOrigin = DiplomaOrigin.Binnenlands);
 
 /// <summary>
 /// The submit use case: create the <see cref="Registration"/> aggregate (INGEDIEND), persist it,
@@ -18,13 +20,14 @@ public sealed class SubmitRegistration(IRegistrationStore store, IWorkflowClient
     {
         ArgumentNullException.ThrowIfNull(command);
 
-        var registration = Registration.Submit(command.Bsn);
+        var registration = Registration.Submit(command.Bsn, command.DiplomaOrigin);
 
         // Persist before starting the process so the worker can correlate the OpenZaakAanmaken
         // job back to an aggregate that already exists (ADR-0009).
         await store.SaveAsync(registration, ct);
 
-        var processInstanceId = await workflow.StartRegistrationProcessAsync(registration.Id, ct);
+        var processInstanceId = await workflow.StartRegistrationProcessAsync(
+            registration.Id, registration.DiplomaOrigin, ct);
         registration.RecordProcessStarted(processInstanceId);
         await store.SaveAsync(registration, ct);
 

services/domain/Big.Domain/DiplomaOrigin.cs

@@ -0,0 +1,17 @@
+namespace Big.Domain;
+
+/// <summary>
+/// Where a zorgprofessional's diploma was issued. It is the input to the diploma-eligibility decision
+/// (S-13): a <see cref="Buitenlands"/> (foreign) diploma routes the registratie through an extra
+/// CBGV-advies assessment step, a <see cref="Binnenlands"/> (domestic) one goes straight to beoordeling.
+/// The decision itself lives in the workflow's DMN, not here (ADR-0016); the domain only carries the
+/// origin and hands it to the process as a start variable.
+/// </summary>
+public enum DiplomaOrigin
+{
+    /// <summary>A Dutch (domestic) diploma. Default for a registration submitted via DigiD.</summary>
+    Binnenlands,
+
+    /// <summary>A foreign diploma (e.g. an eIDAS submission). Triggers the CBGV-advies step.</summary>
+    Buitenlands,
+}

services/domain/Big.Domain/Registration.cs

@@ -7,10 +7,11 @@ namespace Big.Domain;
 /// </summary>
 public sealed class Registration
 {
-    private Registration(RegistrationId id, string bsn)
+    private Registration(RegistrationId id, string bsn, DiplomaOrigin diplomaOrigin)
     {
         Id = id;
         Bsn = bsn;
+        DiplomaOrigin = diplomaOrigin;
         Status = RegistrationStatus.Ingediend;
     }
 
@@ -20,6 +21,10 @@ public sealed class Registration
     /// as the domain payload; the domain never constructs ZGW concepts from it (§8.1).</summary>
     public string Bsn { get; }
 
+    /// <summary>Where the diploma was issued. Rides along to the process as a start variable and
+    /// drives the diploma-eligibility DMN's foreign→CBGV-advies routing (S-13, ADR-0016).</summary>
+    public DiplomaOrigin DiplomaOrigin { get; }
+
     public RegistrationStatus Status { get; private set; }
 
     /// <summary>The Flowable process instance driving this registration, once started.</summary>
@@ -28,11 +33,13 @@ public sealed class Registration
     /// <summary>The zaak the ACL opened for this registration, once the external task has run.</summary>
     public Uri? ZaakUrl { get; private set; }
 
-    /// <summary>Submit a new registration. It begins in <see cref="RegistrationStatus.Ingediend"/>.</summary>
+    /// <summary>Submit a new registration. It begins in <see cref="RegistrationStatus.Ingediend"/>.
-    public static Registration Submit(string bsn)
+    /// The diploma origin defaults to <see cref="DiplomaOrigin.Binnenlands"/> — the common DigiD path;
+    /// a foreign (eIDAS) submission passes <see cref="DiplomaOrigin.Buitenlands"/>.</summary>
+    public static Registration Submit(string bsn, DiplomaOrigin diplomaOrigin = DiplomaOrigin.Binnenlands)
     {
         ArgumentException.ThrowIfNullOrWhiteSpace(bsn);
-        return new Registration(RegistrationId.New(), bsn);
+        return new Registration(RegistrationId.New(), bsn, diplomaOrigin);
     }
 
     /// <summary>Record that the registratie workflow process has been started for this registration.</summary>

services/domain/Big.Infrastructure/FlowableWorkflowClient.cs

@@ -24,15 +24,20 @@ public sealed class FlowableWorkflowClient(HttpClient http, FlowableOptions opti
     private const string BehandelaarGroup = "behandelaar";
     private const string TeamleadGroup = "teamlead";
     private const string RegistrationIdVariable = "registrationId";
+    private const string DiplomaOriginVariable = "diplomaOrigin";
     private const string ZaakUrlVariable = "zaakUrl";
     private const string BesluitVariable = "besluit";
     private const string IngetrokkenMessage = "RegistratieIngetrokken";
 
-    public async Task<string> StartRegistrationProcessAsync(RegistrationId registrationId, CancellationToken ct = default)
+    public async Task<string> StartRegistrationProcessAsync(
+        RegistrationId registrationId, DiplomaOrigin diplomaOrigin, CancellationToken ct = default)
     {
         var request = new StartProcessRequest(
             ProcessDefinitionKey,
-            [new Variable(RegistrationIdVariable, "string", registrationId.ToString())]);
+            [
+                new Variable(RegistrationIdVariable, "string", registrationId.ToString()),
+                new Variable(DiplomaOriginVariable, "string", diplomaOrigin.ToString()),
+            ]);
 
         var created = await PostAsync<StartProcessRequest, ProcessInstance>(
             "service/runtime/process-instances", request, ct)

services/domain/Big.Tests/Fakes.cs

@@ -32,12 +32,15 @@ internal sealed class FakeWorkflowClient(string processInstanceId = "proc-1", Ac
     : IWorkflowClient
 {
     public RegistrationId? StartedFor { get; private set; }
+    public DiplomaOrigin? StartedWithOrigin { get; private set; }
     public string? WithdrawnProcessInstanceId { get; private set; }
 
-    public Task<string> StartRegistrationProcessAsync(RegistrationId registrationId, CancellationToken ct = default)
+    public Task<string> StartRegistrationProcessAsync(
+        RegistrationId registrationId, DiplomaOrigin diplomaOrigin, CancellationToken ct = default)
     {
         onStart?.Invoke(registrationId);
         StartedFor = registrationId;
+        StartedWithOrigin = diplomaOrigin;
         return Task.FromResult(processInstanceId);
     }
 

services/domain/Big.Tests/FlowableWorkflowClientTests.cs

@@ -24,7 +24,7 @@ public class FlowableWorkflowClientTests
         var client = Client(capture.Responds(HttpStatusCode.Created, """{"id":"pi-1"}"""));
         var rid = RegistrationId.New();
 
-        var pid = await client.StartRegistrationProcessAsync(rid);
+        var pid = await client.StartRegistrationProcessAsync(rid, DiplomaOrigin.Binnenlands);
 
         Assert.Equal("pi-1", pid);
         Assert.Equal(HttpMethod.Post, capture.Seen!.Method);
@@ -38,6 +38,22 @@ public class FlowableWorkflowClientTests
         Assert.Contains($"\"value\":\"{rid}\"", capture.Body);
     }
 
+    [Theory]
+    [InlineData(DiplomaOrigin.Binnenlands, "Binnenlands")]
+    [InlineData(DiplomaOrigin.Buitenlands, "Buitenlands")]
+    public async Task Start_posts_the_diploma_origin_as_a_process_variable(DiplomaOrigin origin, string expected)
+    {
+        // The diploma origin rides along as a start variable so the workflow's DMN can route foreign
+        // diplomas through CBGV-advies (S-13, ADR-0016).
+        var capture = new RequestCapture();
+        var client = Client(capture.Responds(HttpStatusCode.Created, """{"id":"pi-1"}"""));
+
+        await client.StartRegistrationProcessAsync(RegistrationId.New(), origin);
+
+        Assert.Contains("\"name\":\"diplomaOrigin\"", capture.Body);
+        Assert.Contains($"\"value\":\"{expected}\"", capture.Body);
+    }
+
     [Fact]
     public async Task Start_uses_the_configured_worker_credentials_and_defaults()
     {
@@ -125,7 +141,7 @@ public class FlowableWorkflowClientTests
         var client = Client(capture.Responds(HttpStatusCode.InternalServerError));
 
         await Assert.ThrowsAsync<HttpRequestException>(
-            () => client.StartRegistrationProcessAsync(RegistrationId.New()));
+            () => client.StartRegistrationProcessAsync(RegistrationId.New(), DiplomaOrigin.Binnenlands));
     }
 
     [Fact]
@@ -135,7 +151,7 @@ public class FlowableWorkflowClientTests
         var client = Client(capture.Responds(HttpStatusCode.Created, "null"));
 
         var ex = await Assert.ThrowsAsync<InvalidOperationException>(
-            () => client.StartRegistrationProcessAsync(RegistrationId.New()));
+            () => client.StartRegistrationProcessAsync(RegistrationId.New(), DiplomaOrigin.Binnenlands));
         Assert.Contains("empty process-instance", ex.Message);
     }
 

services/domain/Big.Tests/RegistrationTests.cs

@@ -16,6 +16,15 @@ public class RegistrationTests
         Assert.Null(registration.ProcessInstanceId);
     }
 
+    [Fact]
+    public void A_registration_defaults_to_a_domestic_diploma()
+        => Assert.Equal(DiplomaOrigin.Binnenlands, Registration.Submit("123456782").DiplomaOrigin);
+
+    [Fact]
+    public void A_foreign_diploma_submission_records_its_origin()
+        => Assert.Equal(DiplomaOrigin.Buitenlands,
+            Registration.Submit("123456782", DiplomaOrigin.Buitenlands).DiplomaOrigin);
+
     [Theory]
     [InlineData("")]
     [InlineData("   ")]

services/domain/Big.Tests/SubmitRegistrationTests.cs

@@ -25,6 +25,19 @@ public class SubmitRegistrationTests
         Assert.Equal(2, store.SaveCount);
     }
 
+    [Fact]
+    public async Task Submitting_a_foreign_diploma_carries_its_origin_to_the_process()
+    {
+        var store = new FakeRegistrationStore();
+        var workflow = new FakeWorkflowClient();
+        var handler = new SubmitRegistration(store, workflow);
+
+        var id = await handler.HandleAsync(new SubmitRegistrationCommand("123456782", DiplomaOrigin.Buitenlands));
+
+        Assert.Equal(DiplomaOrigin.Buitenlands, (await store.GetAsync(id))!.DiplomaOrigin);
+        Assert.Equal(DiplomaOrigin.Buitenlands, workflow.StartedWithOrigin);
+    }
+
     [Fact]
     public async Task Rejects_a_null_command_without_touching_the_store_or_workflow()
     {

tests/acceptance/Features/EenDiplomaRouteren.feature

@@ -0,0 +1,19 @@
+# language: en
+# Drives S-13 (#14). A registration's diploma origin decides its route: a domestic (Binnenlands)
+# diploma goes straight to beoordeling, a foreign (Buitenlands) one is routed through an extra
+# CBGV-advies step (PRD flow 4). The decision itself is a DMN evaluated inside the workflow
+# (ADR-0016); the domain's part — verified here — is carrying the origin into the process so the DMN
+# can route on it. The DMN evaluation and the CBGV routing are verified live (verify-domain).
+Feature: Een diploma op herkomst routeren
+  Als register wil ik een aanvraag met een buitenlands diploma extra laten toetsen
+  zodat een CBGV-advies wordt ingewonnen voordat een behandelaar beoordeelt.
+
+  Scenario: Een binnenlands diploma start de registratie als binnenlands
+    Given a zorgprofessional with a "Binnenlands" diploma
+    When they submit their registration
+    Then the registratie process is started carrying a "Binnenlands" diploma
+
+  Scenario: Een buitenlands diploma start de registratie als buitenlands
+    Given a zorgprofessional with a "Buitenlands" diploma
+    When they submit their registration
+    Then the registratie process is started carrying a "Buitenlands" diploma

tests/acceptance/Steps/EenDiplomaRouterenSteps.cs

@@ -0,0 +1,36 @@
+using Acceptance.Support;
+using Big.Application;
+using Big.Domain;
+using Reqnroll;
+using Xunit;
+
+namespace Acceptance.Steps;
+
+/// <summary>Bindings for <c>EenDiplomaRouteren.feature</c> (S-13). Drives the submit use case against
+/// in-memory ports and asserts the registratie process is started carrying the diploma origin — the
+/// domain's contribution to flow 4. The DMN evaluation and the foreign→CBGV-advies routing it drives
+/// are verified live (verify-domain); one instance per scenario.</summary>
+[Binding]
+[Scope(Feature = "Een diploma op herkomst routeren")]
+public sealed class EenDiplomaRouterenSteps
+{
+    private readonly InMemoryRegistrationStore _store = new();
+    private readonly InMemoryWorkflowClient _workflow = new();
+    private DiplomaOrigin _origin;
+
+    [Given("a zorgprofessional with a \"(.*)\" diploma")]
+    public void GivenAZorgprofessionalWithADiploma(string origin)
+        => _origin = Enum.Parse<DiplomaOrigin>(origin, ignoreCase: true);
+
+    [When("they submit their registration")]
+    public async Task WhenTheySubmitTheirRegistration()
+        => await new SubmitRegistration(_store, _workflow).HandleAsync(
+            new SubmitRegistrationCommand("123456782", _origin));
+
+    [Then("the registratie process is started carrying a \"(.*)\" diploma")]
+    public void ThenTheProcessIsStartedCarryingTheDiploma(string expected)
+    {
+        Assert.NotNull(_workflow.StartedFor);
+        Assert.Equal(Enum.Parse<DiplomaOrigin>(expected, ignoreCase: true), _workflow.StartedWithOrigin);
+    }
+}

tests/acceptance/Support/InMemoryDomainPorts.cs

@@ -12,11 +12,14 @@ public sealed class InMemoryWorkflowClient : IWorkflowClient
     public const string StartedProcessInstanceId = "proc-acc-1";
 
     public RegistrationId? StartedFor { get; private set; }
+    public DiplomaOrigin? StartedWithOrigin { get; private set; }
     public string? WithdrawnProcessInstanceId { get; private set; }
 
-    public Task<string> StartRegistrationProcessAsync(RegistrationId registrationId, CancellationToken ct = default)
+    public Task<string> StartRegistrationProcessAsync(
+        RegistrationId registrationId, DiplomaOrigin diplomaOrigin, CancellationToken ct = default)
     {
         StartedFor = registrationId;
+        StartedWithOrigin = diplomaOrigin;
         return Task.FromResult(StartedProcessInstanceId);
     }
 

workflows/diploma-eligibility.dmn

@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!-- Diploma-eligibility decision (S-13, ADR-0016). Evaluated inline by the registratie process as a
+     BPMN businessRuleTask: given the diploma's origin, it sets the `route` the process should take.
+     A foreign (Buitenlands) diploma routes through the extra CBGV-advies assessment step; a domestic
+     one (or anything else) goes DIRECT to beoordeling. FIRST hit policy: the foreign rule wins, and
+     the empty-input catch-all is the default. -->
+<definitions xmlns="https://www.omg.org/spec/DMN/20191111/MODEL/"
+             xmlns:flowable="http://flowable.org/dmn"
+             id="diplomaEligibilityDefinitions"
+             name="Diploma eligibility"
+             namespace="http://respellion.nl/big/dmn">
+  <decision id="diploma-eligibility" name="Diploma eligibility">
+    <decisionTable id="dt-diploma-eligibility" hitPolicy="FIRST">
+      <input id="in-origin" label="Diploma origin">
+        <inputExpression id="ie-origin" typeRef="string">
+          <text>diplomaOrigin</text>
+        </inputExpression>
+      </input>
+      <output id="out-route" label="Route" name="route" typeRef="string"/>
+      <rule id="rule-foreign">
+        <inputEntry id="rule-foreign-in">
+          <text>"Buitenlands"</text>
+        </inputEntry>
+        <outputEntry id="rule-foreign-out">
+          <text>"CBGV_ADVIES"</text>
+        </outputEntry>
+      </rule>
+      <rule id="rule-default">
+        <inputEntry id="rule-default-in">
+          <text></text>
+        </inputEntry>
+        <outputEntry id="rule-default-out">
+          <text>"DIRECT"</text>
+        </outputEntry>
+      </rule>
+    </decisionTable>
+  </decision>
+</definitions>

workflows/registratie.bpmn

@@ -1,6 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <definitions xmlns="http://www.omg.org/spec/BPMN/20100524/MODEL"
              xmlns:flowable="http://flowable.org/bpmn"
+             xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
              xmlns:bpmndi="http://www.omg.org/spec/BPMN/20100524/DI"
              xmlns:omgdc="http://www.omg.org/spec/DD/20100524/DC"
              xmlns:omgdi="http://www.omg.org/spec/DD/20100524/DI"
@@ -20,7 +21,11 @@
        has not picked the task up within 14 days it fires a parallel token to an external-worker task
        (BeoordelingEscaleren); the Workflow Client reassigns the still-open Beoordelen task from the
        behandelaar group to teamlead (ADR-0015). The Beoordelen task stays open throughout — the timer
-       only changes who may claim it. -->
+       only changes who may claim it.
+       S-13 adds diploma-eligibility routing: between OpenZaakAanmaken and Beoordelen a DMN
+       businessRuleTask evaluates the `diploma-eligibility` decision on the diplomaOrigin start
+       variable; an exclusive gateway routes a foreign diploma through the CBGV-advies user task
+       before Beoordelen, a domestic one straight there (ADR-0016). -->
   <message id="Message_Ingetrokken" name="RegistratieIngetrokken"/>
 
   <process id="registratie" name="Registratie ontvangen" isExecutable="true">
@@ -33,7 +38,35 @@
                  flowable:type="external-worker"
                  flowable:topic="OpenZaakAanmaken"/>
 
-    <sequenceFlow id="flow2" sourceRef="OpenZaakAanmaken" targetRef="Beoordelen"/>
+    <sequenceFlow id="flow2" sourceRef="OpenZaakAanmaken" targetRef="DiplomaEligibiliteit"/>
+
+    <!-- S-13: evaluate the diploma-eligibility DMN inline (ADR-0016). Flowable runs the deployed
+         `diploma-eligibility` decision against the diplomaOrigin start variable and sets the `route`
+         output as a process variable. The gateway then routes a foreign diploma through CBGV-advies,
+         a domestic one straight to Beoordelen. -->
+    <businessRuleTask id="DiplomaEligibiliteit" name="Diploma-eligibiliteit bepalen" flowable:type="dmn">
+      <extensionElements>
+        <flowable:field name="decisionTableReferenceKey">
+          <flowable:string><![CDATA[diploma-eligibility]]></flowable:string>
+        </flowable:field>
+      </extensionElements>
+    </businessRuleTask>
+
+    <sequenceFlow id="flow2a" sourceRef="DiplomaEligibiliteit" targetRef="RouteOpDiploma"/>
+
+    <exclusiveGateway id="RouteOpDiploma" name="Buitenlands diploma?" default="flowDirect"/>
+
+    <sequenceFlow id="flowCbgv" sourceRef="RouteOpDiploma" targetRef="CBGVAdvies">
+      <conditionExpression xsi:type="tFormalExpression"><![CDATA[${route == 'CBGV_ADVIES'}]]></conditionExpression>
+    </sequenceFlow>
+
+    <!-- The extra CBGV-style assessment for foreign diplomas (PRD flow 4). A CBGV medewerker
+         completes it, after which the case continues to the regular beoordeling. -->
+    <userTask id="CBGVAdvies" name="CBGV-advies" flowable:candidateGroups="cbgv"/>
+
+    <sequenceFlow id="flowCbgvNaarBeoordelen" sourceRef="CBGVAdvies" targetRef="Beoordelen"/>
+
+    <sequenceFlow id="flowDirect" sourceRef="RouteOpDiploma" targetRef="Beoordelen"/>
 
     <userTask id="Beoordelen" name="Beoordelen" flowable:candidateGroups="behandelaar"/>
 
@@ -77,53 +110,79 @@
         <omgdc:Bounds x="100" y="100" width="30" height="30"/>
       </bpmndi:BPMNShape>
       <bpmndi:BPMNShape id="s_task" bpmnElement="OpenZaakAanmaken">
-        <omgdc:Bounds x="200" y="85" width="120" height="60"/>
+        <omgdc:Bounds x="180" y="85" width="120" height="60"/>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="s_dmn" bpmnElement="DiplomaEligibiliteit">
+        <omgdc:Bounds x="350" y="85" width="120" height="60"/>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="s_route" bpmnElement="RouteOpDiploma" isMarkerVisible="true">
+        <omgdc:Bounds x="520" y="90" width="40" height="40"/>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="s_cbgv" bpmnElement="CBGVAdvies">
+        <omgdc:Bounds x="500" y="200" width="120" height="60"/>
       </bpmndi:BPMNShape>
       <bpmndi:BPMNShape id="s_beoordelen" bpmnElement="Beoordelen">
-        <omgdc:Bounds x="390" y="85" width="120" height="60"/>
+        <omgdc:Bounds x="630" y="85" width="120" height="60"/>
       </bpmndi:BPMNShape>
       <bpmndi:BPMNShape id="s_end" bpmnElement="end">
-        <omgdc:Bounds x="580" y="100" width="30" height="30"/>
+        <omgdc:Bounds x="810" y="100" width="30" height="30"/>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="s_ingetrokken" bpmnElement="Ingetrokken">
+        <omgdc:Bounds x="690" y="135" width="30" height="30"/>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="s_endIngetrokken" bpmnElement="endIngetrokken">
+        <omgdc:Bounds x="690" y="250" width="30" height="30"/>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="s_escaleerTimer" bpmnElement="EscaleerTimer">
+        <omgdc:Bounds x="700" y="70" width="30" height="30"/>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="s_escaleerBeoordeling" bpmnElement="EscaleerBeoordeling">
+        <omgdc:Bounds x="800" y="20" width="120" height="60"/>
+      </bpmndi:BPMNShape>
+      <bpmndi:BPMNShape id="s_endEscaleren" bpmnElement="endEscaleren">
+        <omgdc:Bounds x="970" y="35" width="30" height="30"/>
       </bpmndi:BPMNShape>
       <bpmndi:BPMNEdge id="e_flow1" bpmnElement="flow1">
         <omgdi:waypoint x="130" y="115"/>
-        <omgdi:waypoint x="200" y="115"/>
+        <omgdi:waypoint x="180" y="115"/>
       </bpmndi:BPMNEdge>
       <bpmndi:BPMNEdge id="e_flow2" bpmnElement="flow2">
-        <omgdi:waypoint x="320" y="115"/>
+        <omgdi:waypoint x="300" y="115"/>
-        <omgdi:waypoint x="390" y="115"/>
+        <omgdi:waypoint x="350" y="115"/>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge id="e_flow2a" bpmnElement="flow2a">
+        <omgdi:waypoint x="470" y="115"/>
+        <omgdi:waypoint x="520" y="110"/>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge id="e_flowDirect" bpmnElement="flowDirect">
+        <omgdi:waypoint x="560" y="110"/>
+        <omgdi:waypoint x="630" y="115"/>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge id="e_flowCbgv" bpmnElement="flowCbgv">
+        <omgdi:waypoint x="540" y="130"/>
+        <omgdi:waypoint x="540" y="200"/>
+      </bpmndi:BPMNEdge>
+      <bpmndi:BPMNEdge id="e_flowCbgvNaarBeoordelen" bpmnElement="flowCbgvNaarBeoordelen">
+        <omgdi:waypoint x="620" y="230"/>
+        <omgdi:waypoint x="660" y="230"/>
+        <omgdi:waypoint x="660" y="145"/>
       </bpmndi:BPMNEdge>
       <bpmndi:BPMNEdge id="e_flow3" bpmnElement="flow3">
-        <omgdi:waypoint x="510" y="115"/>
+        <omgdi:waypoint x="750" y="115"/>
-        <omgdi:waypoint x="580" y="115"/>
+        <omgdi:waypoint x="810" y="115"/>
       </bpmndi:BPMNEdge>
-      <bpmndi:BPMNShape id="s_ingetrokken" bpmnElement="Ingetrokken">
-        <omgdc:Bounds x="435" y="135" width="30" height="30"/>
-      </bpmndi:BPMNShape>
-      <bpmndi:BPMNShape id="s_endIngetrokken" bpmnElement="endIngetrokken">
-        <omgdc:Bounds x="435" y="220" width="30" height="30"/>
-      </bpmndi:BPMNShape>
       <bpmndi:BPMNEdge id="e_flow4" bpmnElement="flow4">
-        <omgdi:waypoint x="450" y="165"/>
+        <omgdi:waypoint x="705" y="165"/>
-        <omgdi:waypoint x="450" y="220"/>
+        <omgdi:waypoint x="705" y="250"/>
       </bpmndi:BPMNEdge>
-      <bpmndi:BPMNShape id="s_escaleerTimer" bpmnElement="EscaleerTimer">
-        <omgdc:Bounds x="480" y="70" width="30" height="30"/>
-      </bpmndi:BPMNShape>
-      <bpmndi:BPMNShape id="s_escaleerBeoordeling" bpmnElement="EscaleerBeoordeling">
-        <omgdc:Bounds x="580" y="20" width="120" height="60"/>
-      </bpmndi:BPMNShape>
-      <bpmndi:BPMNShape id="s_endEscaleren" bpmnElement="endEscaleren">
-        <omgdc:Bounds x="760" y="35" width="30" height="30"/>
-      </bpmndi:BPMNShape>
       <bpmndi:BPMNEdge id="e_flow5" bpmnElement="flow5">
-        <omgdi:waypoint x="495" y="70"/>
+        <omgdi:waypoint x="715" y="70"/>
-        <omgdi:waypoint x="495" y="50"/>
+        <omgdi:waypoint x="715" y="50"/>
-        <omgdi:waypoint x="580" y="50"/>
+        <omgdi:waypoint x="800" y="50"/>
       </bpmndi:BPMNEdge>
       <bpmndi:BPMNEdge id="e_flow6" bpmnElement="flow6">
-        <omgdi:waypoint x="700" y="50"/>
+        <omgdi:waypoint x="920" y="50"/>
-        <omgdi:waypoint x="760" y="50"/>
+        <omgdi:waypoint x="970" y="50"/>
       </bpmndi:BPMNEdge>
     </bpmndi:BPMNPlane>
   </bpmndi:BPMNDiagram>