step change

The concept has been borrowed from mathematics and technology terminology, from step function.

step change (plural step changes)

1. A sudden, discontinuous change.
   • 2007 January 10, Michael McCarthy, Stephen Castle, “http://www.independent.co.uk/environment/climate-change/eu-climate-change-will-transform-the-face-of-the-continent-431491.html”, in The Independent:

     The report, stark and uncompromising, marks a step change in Europe's own role in pushing for international action to combat climate change, as it will be used in a bid to commit the EU to ambitious new targets for cutting emissions of greenhouse gases.

   • 2019 November 6, Philip Haigh, “Analysis”, in Rail, page 32:

     This 'pre-funding' helps smooth payments and avoids step-changes in charges to operators, according to ORR [Office of Rail and Road].

• paradigm shift
• quantum leap
• quantum jump

• “step change”, in Lexico, Dictionary.com; Oxford University Press, 2019–2022.