Prefactoring

7.3. Migrating to the New System

Sam and I need to determine how to phase the new computer system into production. Often systems under development can be run in parallel with older systems. When a new system produces exactly the same results that the old system does, the old system is retired during a quiescent period, such as when the business is closed. We will take this approach with Sam's system.

7.3.1. Loading Current Data

For Sam's system, we need a way to get the current data into the system. That data includes the discs in the inventory, the customers, and the current rental data.

I met Sam for coffee. Sam is a coffee connoisseur. He can spout off the differences between beans from each country and each growing region. I can barely differentiate between regular and decaf. He ordered a grande. I wanted a large coffee (it might be a long discussion). When I ordered a supersize cup, the clerk looked at me quizzically.

"Sam, I've been thinking about how we're going to start up the system," I stated.

"I've been wondering about that also," Sam said.

"Since everything is currently on paper, you'll need to convert the information to digital form. I can specify a format that the information can be converted into so that it can be read into the system," I suggested.

"I'll take a look around for services that can scan in my current index cards to create these files," he offered.

"It will be hard to capture the current rentals. It will take time to scan the index cards. By the ...