Which is responsible for the production of the service design package (SDP)?

Service portfolio management is responsible for evaluating and governing which services are offered across the service portfolio, not for producing design documentation for individual services.

Service catalogue management maintains the service catalogue of live and available services, which contains operational information rather than design specifications for new services.

Design coordination orchestrates and coordinates all service design activities and ensures the SDP is completed, but the overall responsibility for producing the SDP belongs to the service design stage as a whole.

Service design as a lifecycle stage is responsible for producing the service design package, which documents requirements, design decisions, resource plans, and transition plans for a new or changed IT service. The SDP is the main output passed from service design to service transition to guide implementation. Accountability for the SDP sits with the service design stage, not any single process within it.