Walter Sherwart and W. Edwards Deming were two American engineers who founded modern statistical quality control. Their work with the Japanese after WW2 led to Lean manufacturing principles and ultimately to DevOps.
The PDCA cicle can be thought of as this, "State your problem in plain English and then follow a checklist."
Plan - Establish processes and objectives for doing your work
Do - Do the work you planned in the "Plan" phase
Check - Do a rigorous check on the data gathered from the "Do Phase"
Act (Adjust) - Improve the process based on data from "Do" and "Check"
Don't short change these steps. When planning, write out your plans, encourage collaboration. A plan has a set of steps, a timeline. A complex plan needs a RACI chart. Before you jump into a project, before you create stories, plan how you will manage the project.
When you are doing the task, keep to the RACI. The doer is responsible, but one person is accountable.
Perform checks - run tests, benchmarks. Part of your plan will be figuring out how you will check, and some of your checks you will need to add once you've finished the "Do" portion.
Act on your checks. Iterate, use the feedback from your checks to decide if you are done, or if you need to refine the plan and start again.