They are different products for different jobs, and "replace" only applies to one part of IID's use:
- IIB / App Connect Enterprise (ACE) is IBM's integration server (ESB): message flows, protocol bridging, transformation, routing - the enterprise integration layer, independent of BPM.
- Integration Designer (IID) is the design tool of BAW Advanced for SCA modules: BPEL processes, mediation modules, adapters, Advanced Integration Services called by BPDs.
What happened: IBM stopped investing in the Advanced (SCA / BPEL) layer; BAW Advanced still exists on traditional WebSphere but is not part of Cloud Pak for Business Automation containers. The integration role that IID's mediation modules and adapters played is now played by App Connect Enterprise (also available inside the Cloud Pak for Integration and callable from CP4BA), and the orchestration role of BPEL by service flows in BAW, ACE flows, or - for long-running system processes - BPDs without human tasks. So: IIB / ACE replaces IID's integration function, service flows and BPDs absorb its orchestration function; nothing replaces BPEL one-to-one.
Practical guidance: keep existing IID assets on BAW Advanced (traditional) as long as they run; for new integrations use REST external services to ACE / API-managed endpoints; plan the migration of BPEL processes to service flows or ACE before moving to containers (question 1408 lists what IID was used for, to inventory).
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