For buyers contracting authority
Pick 72221000 when the deliverable is business-level analysis, not technology design and not the build. A contracting authority uses it to commission a requirements study, a process review, an options appraisal, or a business case before committing to a larger programme. The accepted output is the report and the recommendation.
The boundary that trips authorities is the IT-flavoured sibling. Information systems strategic review and planning (72222000) is for shaping the IT strategy itself; information technology requirements review (72223000) is for pinning down system requirements. Choose 72221000 when the analysis is about the business problem and how the organisation operates, even if technology is part of the answer.
Project management consultancy (72224000) is the other near neighbour: that is advice on running the delivery, while 72221000 is advice on what the delivery should achieve. Where a single contract folds analysis into a wider advisory panel, set the primary CPV code by the dominant deliverable rather than the whole bundle. Several of the example titles below show it bought as a line within a broader consultancy framework, so check whether an existing framework already covers the work before opening a fresh procurement.