One investment banking client asked Z/Yen to conduct a swift survey of product control functions in 9 investment banks in order to inform a business process re-engineering project. Running against a two week timescale, Z/Yen's finance team managed to involve the banks in a fast, co-operative exchange of views on product control - how to do daily P&L's, the importance of balance sheet reconciliation, what is the role of technology, how to link product control to financial reporting? The end results indicated that independent, global product control worked well; so did product control as an operational service. Mixed models seemed to be less effective. We thank all the banks who came forward so helpfully, enabling Z/Yen to control this tight-deadline project effectively.