2.15 NS&I required SBS to deliver its Individual Savings Account (ISA) product by 6 April 1999, six days after NS&I transferred all of its operational staff and assets to SBS. To meet that target date, SBS started work on the ISA after being selected as preferred bidder in December 1998. Following a benchmarking exercise, SBS selected Thaler, a commercially available banking platform on which to run the ISA product. In April 1999 SBS took on the risk of operating NS&I's products. In IT terms each product ran on separate customised software. Before procuring the deal, NS&I had commenced a Business Process Re-engineering programme (BPR) which SBS planned to use. SBS's due diligence, however, before contract signature indicated that NS&I's BPR was unlikely to deliver in line with the plans. After the contract started SBS discovered the technology behind NS&I's BPR was unable to deliver a re-engineered IT system.