Project inflation is to program management what scope inflation is to project management.
In other words, project inflation is when new projects pop up out of nothing in a program, due to changes, in the middle of the program, by the client.
Project inflation often delays the delivery of the whole program, because of priority shuffling and because of increased inter-project dependencies. It is the responsibility of the program manager to control project inflation, by creating a more rigid process for change requests during the course of the program.