step change 
noun
(In business or politics) a significant change in policy or attitude, especially one that results in an improvement or increase.There has been a step change in politics in this country since the war on Iraq, and the movement against it....
- The Commission says the Government's 10-year transport plan - published last year - offers ‘long awaited focus on integrated policies and a step change in levels of investment’.
- We look at companies that are looking to raise capital to fund a step change in their business.