Consultants need to assist Managers and Employees work together to Map out what their current processes are and draw out new innovative solutions which takes account of what is of real value to all internal and external customers. This is a "Lean approach" to consulting and is diametrically opposed to the "Audit approach" followed by many consultants.You said it exactly right. I would say most consultants now are very poorly used - maybe not using them would be better. But using consultants the right way (to coach leaders, to provide insight from the outside, to provide specific expertise) is very valuable if you get the right consultants.
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A skilled consultant can bring together cross functional teams to both discuss and resolve difficult even politically charged issues and problems within the organization. A skilled and experienced Lean consultant can also coach Managers and Employees as they seek to use Lean thinking, tools and methodology in their own work space. Good consultants facilitate and coach teams as they find their own solutions to problems they have identified themselves.
I do think there is also a problem that many consultants now are focused on the wrong style (how to sell more consulting, spreadsheet management, not developing internal expertise, not having an understanding of variation or respect for people...).
Related: Management Consulting Failures - Toyota Production System, Lean Manufacturing... Consultants - Problems with Management and Business Books
