Just in time system and Six Sigma
In six sigma we know that customer focus is really important. In lean manufacturing I came across a process which can really eliminate high storing cost. The process is called just in time (JIT). There has to be "quick communication" in this process. This is required as old stock gets over one can quickly call for new one, eliminating the need of storing or buy a warehouse. Dell is one of the companies that have highly benefited from this system and achieved a competitive edge. This technique is also used by Toyota. It was first started at Ford.
This system is not mentioned in six sigma but can be intergrated in the system in the "Improve" stage of DMAIC process to reduce cost. This could be an option.
This system may not work in all industries but for the one where it works, it can bring great sot benefit.
Though six sigma and lean manufacturing have some different policies, many people are bringing them together with lean six sigma. This shows that both can be combined.