Final answer:
In the system implementation phase of the systems development life cycle (SDLC), parallel installation is used to run the new system alongside the old one until it has been tested and is fully operational.
Step-by-step explanation:
In the system implementation phase of the systems development life cycle (SDLC), with parallel installation, the new system runs alongside the old one until it has been tested and is fully operational.
This type of installation allows for a smooth transition from the old system to the new one. It minimizes disruptions to the organization's operations and allows for testing and debugging of the new system before fully replacing the old system.
For example, in a manufacturing environment, a new production system might be implemented parallel to the existing system. The new system would be gradually phased in and tested while keeping the old system operational to ensure a smooth transition.