Yes there are
I have consulted a number of small and medium sized family companies with Lean Six Sigma to improve business performance. When correctly applied Lean Six Sigma enables a company to perform beyond its natural ability. Unfortunately very few business leaders have the courage to accept that their organisation is not underperforming, it is just performing at its normal and natural ability.
Many of the companies I have worked with apply the natural method to improve performance: Identify a problem and Fix it. This is the method most companies default to and are able to understand. Typically improvements done this way are temporary.
The Lean Six Sigma approach to business improvement is wider. Instead of a simple Identify and Fix (and return to old behavior) method Lean Six Sigma aims at measurable and permanent improvements. This is achieved with the Define, Measure, Analyze, Improve and Control DMAIC method. The natural Identify and Fix would in this context be a Define and Improve method.
In DMAIC the problem is first Defined, then current state is Measured to be able to verify improvement after project, root causes for problem are Analyzed, problem is Improved and finally an out of Control plan is created to ensure corrective actions are taken when the process is showing signs of returning to old behavior.
The problem with Lean Six Sigma that leads to less efficiency is the lack of tools and methods to convince entrepreneurs to really trust DMAIC is better than Identify and Fix.
Very few business leaders see the value in measuring and controlling a process when they are looking for a quick fix. When the Lean Six Sigma project has achieved the improvement many times the control part is left out for various reasons. As a result the achieved improvement is only temporary and the business owner has a good argumentation to why Lean Six Sigma is a waste of time, e.g leads to lower efficiency.
If Lean Six Sigma is applied without proper facilitation and without respect for the principles it is built upon it will result in less efficiency