Ford Chief Operating Officer Mark Fields talked to the Motley Fool in New York last month. Photo: Rex Moore/The Motley Fool.

It's official: Ford (F -1.16%) announced on Thursday that CEO Alan Mulally, 68, will retire on July 1. 

As we've all expected for a while now, his replacement will be Chief Operating Officer Mark Fields, a 25-year Ford veteran who has had successful runs leading several of the company's key business units.

Does this mean that Ford is in for a major change in direction? Not likely. Here's why.

Fields was a leading architect of Ford's transformation
Mulally is known most of all for the "One Ford" plan. One Ford was the blueprint for the company's turnaround, and it continues to serve as the basis for Ford's ongoing approach around the world.

One Ford grew out of an earlier plan called "The Way Forward," which was the automaker's blueprint for transforming its money-losing North American division into a source of sustainable profits. 

The first version of that plan was created in 2005, before Mulally arrived. Who created it? Several senior Ford executives were involved, but Fields was its chief architect and the one who sold it to Ford's board of directors.

Fields was running Ford's North American and South American regions at the time. He was the operating guy who made the turnaround happen -- who implemented One Ford and brought North America from steady losses to a 10% operating profit margin. 

So will Fields change the plan? Probably not, as he has been a key participant since the beginning.

Mulally's most important achievement won't be unwound
In announcing the transition at a press conference on Thursday morning, Executive Chairman Bill Ford repeatedly emphasized how Mulally had led a sea change in Ford's culture, and how that change was key to the company's turnaround.

I wrote about the importance of that change recently, and it was something that Mulally reemphasized to me when we spoke last week. 

It's clear that Fields fully buys in to what he calls the "working together" culture at Ford. It's also clear that Bill Ford, who said on Thursday that he regards himself as the "keeper of Ford's institutional memory," will work closely with Fields to make sure that things stay on track.

So how will Fields change Ford?
It's hard to say, and we may not know for a while. But in the near term, I don't think things will change very much. Given Ford's recent run of success, that's a good thing.

But some sort of change is likely, because as Fields pointed out on Thursday, he and Mulally are different people with different approaches. Mulally came to Ford after spending much of his career at Boeing. He did not have an intense interest in cars or the car business.

But Fields is a Ford guy through and through -- and a product guy, and a "car guy." Fields has a passion for cars and the car business, and some very clear ideas about the kinds of products Ford should offer. That may not mean big changes are on the way, but it's something to keep in mind. 

I don't think we'll see dramatic changes to Ford's product-development approach in the near term -- after all, Fields has been running the automaker's global new-product programs (along with much of the rest of Ford) for over a year now as chief operating officer.

But in time, the new boss may be seen as a more aggressive driver of certain aspects of Ford's new vehicles. It won't be so much a sea change as a shift in emphasis, a difference in style.

Fields often talks about "accelerating" Ford's rate of innovation, its product plans, and so forth. Again, I don't think this is meaningfully different from Mulally's approach, but it's possible Fields will push to shorten Ford's product cycles around the world.

The upshot: A boring transition that Ford's shareholders should cheer
How do you replace an iconic CEO?

As Bill Ford emphasized on Thursday, the process of replacing what he called a "Hall of Fame" CEO is often very messy. But thanks to years of careful planning, Ford's transition from the Mulally era to the Fields era is looking about as tidy as it gets. 

From left to right, Alan Mulally, Bill Ford, and Mark Fields at a press conference announcing the company's leadership transition on Thursday. All three emphasized that a smooth transition was under way. Photo: Ford

For over a year, Ford has been signaling that Fields was the leading candidate to replace Mulally. When he was given the COO role, it was seen as something of an audition for the CEO job, or alternatively, as a way for him to functionally take charge of the company while Mulally was still there to guide and mentor him.

Apparently, Bill Ford, Alan Mulally, and Ford's board were all happy with his performance in that audition, because he got the gig. Later this year, we'll get our first glimpse at what he plans to do with it.