I just completed my 13th year (or about 100 in corporate pilot years) with a 91 department in what would be considered a growth industry. There's simply no way in predicting what will happen down the road, you just have to hope for the best or, if things appear shaky, chances are your gut is right and it's time for a change. Guys that had 30 or 40 years with the same department have found themselves SOL just as they were about to cross the finish line. Bizav is littered with established departments that ended up shutting down for a myriad of reasons. I don't think corporate aviation will go away anytime soon, but the companies who do decide to go that route are more and more cautious once they get in. Good luck.