Use the new system as the same time as the old system to compare the results. This is known as ……

System analysis is the process of gathering data, interpreting information, identifying issues and using the results to recommend or develop possible system improvements in a business or organizatioin.

Closely related to System analysis is systems development life cycle (SDLC), which is a four-phase model (planning, analysis, design, and implementation) used in all information systems development projects.