During which phase of dmaic (define, measure, analyze, improve, control) is the sole purpose to demonstrate, with fact and data, that your solutions solve the problem?

DMAIC is an acronym for Define, Measure, Analyze, Improve and Control. It is a procedure intended to enhance and keep up business forms. The period of which the sole intention is to show with actuality and information that your answers take care of your concern is "move forward." 
It alludes to an information driven change cycle utilized for enhancing, streamlining and settling business procedures and outlines. The DMAIC change cycle is the center device used to drive Six Sigma ventures.