Mariana, the IS Manager, Has Just Received a Note from the Accounting

Mariana, the IS manager, has just received a note from the accounting department stating that they wish a new purchasing system could be placed on the priority list. The chief accounting officer (CAO) has just learned that three of their competitors have new purchasing systems. Since purchasing has not been considered a key business function in the past, the CAO is concerned that his department lacks the functional expertise to implement a new purchasing system. She feels that purchasing is becoming a strategic necessity for the company and a new system should be in place by this time next year. The CAO has managed the automation of numerous accounting functions, such as the purchase of a combined general ledger with accounts receivable and accounts payable, the custom development of a just-in-time inventory control system, and the management of a financial projections and stock funds project that was contracted to an outside vendor.
What would you recommend Mariana do? Include in your discussion the design strategy selection process and the important characteristics that apply to the strategy selected.