This month’s $2.35-billion purchase of Ann Arbor-based Duo Security will do more than create some instant millionaires. It should also remind us how differently we can view business success in Michigan today than in years past.

In Michigan’s 20th-century industrial heyday, the most admired companies were those that endured decade after decade. They built huge workforces and imposing headquarters, and they ranked near the top of the Fortune 500 — Ford, General Motors, Dow, Kellogg.