No, this one is not about some new glass colors, nor politics. It’s about massive changes in leadership at the top that keep affecting our industry. But change is a constant, right? Especially in the glass industry.

I am referring, of course, to the changes in management that have occurred during the last 24 to 36 months among the primary manufacturers. Consider this:

Scott Thomsen took over as group vice president for Guardian’s North American flat glass operations on March 1, 2010. He became president of Guardian Glass upon Russ Ebeid’s retirement on September 1 last year. Though Guardian’s plan for and execution of a succession plan has been deliberate and steady, and its new president garnering good reviews, he has still been at the helm less than two years.

PPG has had its fair share of change atop its flat glass empire. Victoria Holt, who had served as vice president of glass and fiberglass, tendered a sudden resignation in September 2010. Gary Danowski, who had served as VP in charge of the company’s performance glazing unit, soon was named vice president of flat glass. But by May of last year, he had moved on to become PPG’s vice president in charge of automotive refinishing in Europe and Richard Beuke took the helm of flat glass as vice president there. Beuke has a long history of growth at PPG, having served as vice president of silicas prior to his new position. He reports to J. Rich Alexander, executive vice president of performance coatings and glass. PPG, too, has long been known for developing home-grown talent and making moves such moves are not unusual for it.

Consider the case of Nippon Sheet Glass (NSG), owners of the Pilkington brand. Stuart Chambers led the company during the acquisition of Pilkington. He was appointed NSG chief in June 2008 and resigned abruptly in August 2009. NSG’s chair Katsuji Fujimoto served as interim president/CEO until Craig Naylor was hired in April 2010. Just 24 months later, Naylor, too, is gone and Keiji Yoshikawa has been named president/CEO.

So which company is the antithesis of all this change? Cardinal, where Roger O’Shaugnessy has been president for the past 45 of its 50 years in business.

So what does this mean? Strong companies always make sure their benches are deep and their leaders able to run new divisions. Many of these moves reflect that. But with such moves there is also subtle and sudden change in perspective.

But what does surprise me is this. In an industry that is almost inert by other industry standards, and where the customers of these companies are second-, third-, fourth- and, in some cases, fifth-generation business owners, it’s amazing to see such change at the top of the glass food chain. It explains why so many people say, rightly or wrongly, that some of the primaries don’t have a “face” to them. They all do, of course, but the faces are just newer than they have ever been before.