In some cases, interactive functions may appear on existing systems.
Mr Balls argued that building on an existing system would be "a more straightforward proposition".
"What the Congress and the president tried to accomplish through reform is to transform the marketplace by building on the existing system," she said.
Ahead of the summit, the Organisation for Economic Co-operation and Development (OECD), proposed to share tax information by building on an existing system set up by the US and five major European economies, but on a global scale.
Building on existing Patient Reported Outcomes Measurement Information System (PROMIS) item banks, the present study aimed to select items to assess panic disorder, social anxiety disorder, obsessive-compulsive disorder, posttraumatic stress disorder, adult attention-deficit hyperactivity disorder, substance use disorder, suicidal thoughts and behaviors, and psychosis.
Additionally, organized emergency services could improve health system efficiency by building on existing informal mechanisms of care.
He said, "At first we were just building solutions to problems we had with existing systems.
However, to make it usable for the Afghan government, the building would require a major overhaul of existing systems, including the expensive heating, ventilation, and air conditioning systems.
