Let’s review the recommended elements of a successful process improvement initiative:

Find A Champion. Without leadership, nothing much will happen. This is normally someone at the highest levels of the company with a passion for improvement.
Find Or Create A Crisis. What is going to motivate you to improve? If there is not strong motivation, things will happen very slowly. A “crisis” in this case is similar to the concept of a BHAG, A Big Hairy Audacious Goal.
Find a mentor. Time is too short to spend reinventing the wheel. Find someone who can get you up the learning curves fast.
Map the Value Stream. Take you major products and product families, and map the process flow from start to finish. Identify areas of improvement without cherry picking.
Create an implementation plan and assign resources. Without resources, in the form of dedicated people, planned Kaizen events, a Process Owner, it will be slow going. It has been estimated that in order to improve quickly enough, you will need between 1% and 3% of your workforce dedicated to process improvement.
Follow the lean roadmap: the Process Maturity Model, Process Champions and Owners, Balanced Scorecard, Standard Work, etc.