After a team develops their Theory of Improvement and identifies their change idea(s), they must test and collect evidence to determine if their change idea(s) has an impact on their Theory of Improvement. One approach to testing a change idea is the Plan-Do-Study-Act or PDSA cycle. PDSA cycles are short in duration and provide opportunities for teams to test a change idea on a small scale before scaling up across their system. Run Charts are another tool that can be used to collect data as a change idea is tested.