A large retailer loses millions of customer records in a major data breach. They must develop and implement a new system which includes new hardware, applications, and storage. Which of the following actions will be most difficult to perform when implementing the new information system?

changing the structure of existing databases that reflect supplier and customer data

writing the programs to create the software

training the employees to use and manage the new system

installing new transaction processing hardware

upgrading the computer systems used by the retail chain