Is enough enough? Do the old rules of the Jack Welch era not work anymore? Does American business need a new playbook? Does today’s volatile, brutally competitive business climate demand a new set of rules and a whole new mindset? (Will this entire article be a series of questions?)

Jack Welch long has stood as a model not only for the can-do American executive but for a way of doing business that revived U.S. business in the 1980s and dominated the world’s economic landscape for a quarter century. His ruthlessly efficient strategy drove General Electric (GE) to high performance. His influence made the Six Sigma methodology popular the world over. He talked about being the leanest and meanest and lowest-cost, and corporate America got out the machete.

Indeed, you’d be hard pressed to find an executive who hasn’t been influenced by Welch’s business teachings. For some time, his formula for success has been agreed upon by American business (at least corporate America).

But corporate America needs a new playbook, says a Fortune magazine (via Fortune/CNNMoney.com) feature this month, as today’s smart CEOs are following a different set of rules, dramatically rethinking the fundamental assumptions that defined Welch and his era.

There is another model. “The rock star of business,” Fortune says, “is no longer the guy atop the FORTUNE 500 (today Rex Tillerson at ExxonMobil), but the very guy those FORTUNE 500 types used to love to ridicule: Steve Jobs at Apple.”

The invention of the iPod has transformed an industry. Dell spectacularly upended Compaq and Hewlett-Packard.
One word: Google. ‘Nuff said.

Yet few big companies paid close enough attention to see that new technologies and business models were negating the power of economies of scale in myriad ways.

The challenges facing U.S. business leaders are greater than ever before — the unpredictable volatility of the markets, the intense competition from China and India — that the rules of the past, to some people, are starting to feel…out of date.

As such, here are seven old rules whose shortcomings, according to Fortune, “have become apparent” and seven replacements that “point toward a new model for success.” While some of the old rules are inspired directly by Welch’s teachings, others are not. In fact, it seems that some of these take Welch’s rules and principles out of context.

Old Rules
1) Big dogs own the street.
2) Be No. 1 or No. 2 in your market.
3) Shareholders rule.
4) Be lean and mean.
5) Rank your players; go with the A’s.
6) Hire a charismatic CEO.
7) Admire my might.

New Rules
1) Agile is best; being big can bite you.
2) Find a niche; create something new.
3) The customer is king.
4) Look out, not in.
5) Hire passionate people.
6) Hire a courageous CEO.
7) Admire my soul.

What do you think? Are the principles Welch touted fundamental tenets of good management that business should follow? Are they the outdated business edicts of a sacred cow? What do you think it takes today to get ahead and stay ahead? What new rules, if any, would you add?