The single most wasteful thing you can do in marketing is try to change a mind once it is made up.Al Ries & Jack Trout  "The 22 Immutable Laws of Marketing"

Ries & Trout may overstate the case, but they do have a point.  Changing a mind once it is made up is difficult - not impossible & sometimes extremely profitable.  Dowdy Oil of Olay had an extreme makeover, a dramatic price-hike, then propelled by the P&G marketing machine, dropped the 'Oil of' & invented the masstige skin-care segment.  Now it's a billion dollar brand.
Often, the hardest thing of all, is changing minds inside the organisation.
Does the new way invalidate the long hours & years spent following well-trodden paths?  Is it another flavour of the month, set to cause more uncertainty & chaos?   Has it been tested? 
The road to internal commitment has many potholes along the way.  From boardroom battles to corridor politics & downing tools, change is a challenge to the norm, a discomforting intrusion to be opposed.  
 
Change before you have to
The Sigmoid Curve shows the necessity to, as Jack Welch says, change before you have to.  The act of change, however necessary, causes a period of doubt & uncertainty, allied with extra costs & dips in productivity, as new ways stumble against entrenched beliefs.  When change happens is instituted while the enterprise is dong well, there is built in resilience during an often messy transition.  If the enterprise is on a downturn, the change will cause deeper, perhaps fatal trauma.  But when the going is good, if it ain't broke, don't fix it thinking comes to the fore.
 
We have found three pre-conditions for successful, timeous change:
• A visionary leader
• Money in the bank
• A burning platform
 
The visionary leader needs to see things before they are apparent.  She listens to the said and feels the unsaid, from the centre to the edges of the ecosystem. She needs to craft a compelling story that she can tell, authentically and memorably.  A story that features change to what purpose, rather than change to what end.   Finding a why that goes beyond the bottom line to a place where passion and potential  meet.  When Cicero made a speech, citizens said how well he spoke, when Demosthenes spoke, citizens said let us march.  She must be Demosthenes.  
Money in the bank is needed to fund the necessary disruption.  While throwing money at a problem can be a disaster, under-funding a possible solution may accelerates the negative spiral. 
A burning platform can be eroding brand share, or confidence, a changing context, a sense of complacency.  It may be hard to spot when everything seems plain sailing.  A leader's job is often to create the crisis.  If the crisis has already hit, there's less money in the bank, less time to right the ship.
Change grows through degrees of co-operation & co-creation, with a renewed shared purpose providing the energy.   The essence of an enterprise may need to change.  Or be modified, or re-interpreted to best serve the emerging future.  Or it may remain.  It does need to be interrogated.
Change happens with a realignment of beliefs & actions.  Rarely easy, it is often necessary.