Conducting your review is a critical step in continuous improvement. You can use a variety of measurements, including observation and statistical analysis, to check on the effectiveness of what you have implemented. Then, because continuous improvement is an investment in your workplace culture and life-long process, you’ll naturally return to stage one: identifying additional areas for improvement.
Remember that “change for the sake of change” is not the desired result here at all. Change for the sake of making things better (such as waste elimination, increased productivity, better results overall) is what we’re after.