How do you implement lean in a union environment? What is the best strategy to approach?

In my opinion, as Lean is waste elimination, it leads to increased efficiency in -among others- manpower.  Increased efficiency in manpower is often translated into reduction of manpower, i.e. retrenchment.  However, that may not be so.  It can also mean retraining & change of job scope, or may even be no change due to increased production due to more competitive pricing.

Anyway, profit-oriented organizations have their goals, and Unions -I suppose- are there to ensure that they do not violate workers rights as they pursue their agendas.  I believe, Lean should be carried out with involvement of all stakeholders, including workers (who are affiliated with the Union).

Management should involve the workers, make them aware of the projects background, the need for efficiency. and how they may be affected.  Management should ask workers for suggestions and together find solutions.  Potentially manpower-reducing projects should not be a "top-secret mission".

Even when there is no other way but to reduce manpower... well, Lean or no Lean it happens... Management should fully respect workers' rights, and if there is violation -Lean or no Lean- Union must defend workers' rights.  But hopefully, the culture of collaboration and communication nurtured through Lean can help all parties to settle things amicably.