How do I use ODM decision services from BAW - decision service artifact vs REST call to Decision Server?

Question

We have Operational Decision Manager next to BAW. Process Designer has a "decision" artifact and ODM has REST endpoints - which should we use to run a ruleset from a BPD, and how do the business objects map?

Answer 1

Two supported routes, chosen by who owns the rules:

• Decision services inside BAW (the Decision artifact: decision tables / rule flows authored in Process Designer, executed by the embedded rule engine): no ODM installation needed, versioned with the snapshot, called as a step in a service flow / BPD with typed mapping. Right for small, process-local rules maintained by the process team.
• ODM Decision Server (rules authored in Decision Center by business analysts, deployed as rule apps): call the ruleset from BAW through its REST endpoint - the Hosted Transparent Decision Service (HTDS) of Decision Server publishes each ruleset with an OpenAPI / Swagger description; import it as a REST external service in BAW and you get the ruleset's input / output parameters as business objects.

# 1. Swagger of a ruleset (Decision Server, HTDS)
GET https://odm-host:9443/DecisionService/rest/api/swagger.json?ruleApp=LoanValidation&ruleset=LoanValidationRules    (or the "API" link in the Decision Server console)
# 2. BAW: External Service > New > "Import from URL / file" -> operation "executeLoanValidationRules"; Server definition = ODM Decision Server (basic auth or the CP4BA identity)
# 3. service flow: map tw.local.loan -> input BO; call; tw.local.decision <- output BO
# JSON of an HTDS call for reference
POST /DecisionService/rest/v1/LoanValidation/1.0/LoanValidationRules/1.0
{ "loan": { "amount": 12000, "duration": 36 }, "borrower": { "creditScore": 720 } }   ->  { "approval": { "approved": true, "reasons": [] } }

On CP4BA, ODM (Decision Server runtime) sits in the same Cloud Pak and the Server definition uses the internal route with the platform identity; Automation Decision Services (ADS) is the newer decision capability with first-class discovery in Studio (no Swagger import). Design rules: keep the ruleset's parameter model stable (a versioned XSD / JSON schema) so that BAW's generated business objects do not churn; version rulesets by ruleApp version and point BAW at a stable path; cache reference-data decisions with service caching; log the decision id returned by ODM (ruleset execution trace) in the instance for audits.

References

• BAW documentation - decision services and REST external services
• CP4BA - Operational Decision Manager and Automation Decision Services with Workflow