Applying Lean system sounds to bring positive results all time. That won't be always the case. If lean is seen as a tool (not as a whole state of beeing and thinking) lean is like a sword, which can cause a lot of damage and suffering. Focusing only on reducing cost might lead to job cutting which will effect people involvement and increase resistance against Lean, whereas if lean is used to enhance product or service value, if it is focussed on the constraint and thus enhances throughput while raising productivity and reducing cost, it will cause a chain reaction of raising demand and competitiveness of a company. Therefore these things can not be considered as Lean fault as a system!! In my point of view I believe that they are kind of negative potential outcomes or obstacles rather than saying they are disadvantages. Lean system is some elements that can be filled from elsewhere such as Systems Thinking or the Theory of Constraints to support overcoming implementation obstacles. A good practice might be to let a group - employees for example- to figure out some future seen barriers and ask them in turn and list them on a flip chart being careful to identify each bitch/moan/obstacle with the name of the person that brought it up. Then asking them to come up with solution that each person answer his own problem. By doing that you will have both back up actions for particular problems with significant simplifications.