It is also possible to access the DMN model instance by the decision definition id using the Repository Service, as the following incomplete test sample code shows:

    1. public void testRepositoryService() {
    2.   String decisionDefinitionId = repositoryService.createDecisionDefinitionQuery()
    3.     .decisionDefinitionKey(DECISION_KEY).singleResult().getId();
    4.   DmnModelInstance modelInstance = repositoryService
    5.     .getDmnModelInstance(decisionDefinitionId);
    6. }

    原文: https://docs.camunda.org/manual/7.9/user-guide/model-api/dmn-model-api/repository-service/