Corporate turnarounds are almost never engineered by a single person. A CEO who takes a failing company and makes it successful again obviously got help from management, a board, along with customers and shareholders. The vision for how a company can change and the execution skills to put the vision to work begin with the chief executive.

Most large turnarounds have several things in common. First, most new CEOs cut staff sharply to reduce costs and exit non-core businesses. Second, most turnarounds begin with a sharpened focus on core skills and products. Troubled companies often move back to their roots. That certainly happened at Starbucks and Ford. Other firms believe that they are missing one or two critical elements to be successful again. Those elements can be built, but are often bought as was the case when HP bought EDS. New CEOs in successful turnarounds often come from outside the corporation’s industry. This may be because outsiders can bring a fresh perspective and the very best CEOs can manage companies in many industries.

There are very few large American companies which have come close to collapse and then become wildly successful again. Most extremely successful US corporations start small and get big. The is certainly the case with Wall Street darlings such as Google (NASDAQ: GOOG), Exxon Mobil (NYSE: XOM, Intel (NASDAQ: INTC), Coca Cola (NYSE: KO), McDonald’s (NYSE: MCD), Wal-Mart NYSE: WMT) and Procter & Gamble (NYSE: PG).

Companies that have been in business for many years before their fortunes decline are the victims of a relatively small number of problems. The first of these is bad management. This has happened at Boeing (NYSE: BA) and Dell (NASDAQ: DELL). Executives often make mistakes in executing their plans. The Boeing’s 787 Dreamliner, for example, has been delayed several times. Dell has had legal problems and, according to some sources, released products it knew were flawed.

Other firms which move from success to failure miss the signs of a sea change in their industries. This happened to Sears (NASDAQ: SHLD) and K-Mart, which failed to see that Wal-Mart’s big box, low price strategy would dominate the market. Sony(NYSE: SNE) was blindsided by new video consoles from Microsoft (NASDAQ: MSFT) and Nintendo after it controlled the market for years with its PS2. Sony also had an important foothold in portable media market with the Walkman. It did not extend that advantage into the digital age. Motorola dominated the high-end of the handset market with its RAZR. The company was nearly ruined when it failed to launch a strong product to capitalize on that success.

Some companies mistakenly believe that their future will be driven by mergers and acquisitions. Often these transactions are undermined by the difficulty of combining two cultures, two sets of products, and two sales and marketing operations. This happened to AMD (NYSE: AMD) when it bought graphic chip company ATI for $5.4 billion in 2006. AMD has never recovered from its inability to find ways to use ATI’s R&D – worse it was saddled with unbearable debt. The Boston Scientific (NYSE: BSX) buyout of rival Guidant for over $27 billions failed. The two companies could not find the efficiencies that would drive lower costs and higher sales.

The last major reasons that large companies falter to the edge of extinction is market conditions. It would was impossible for airlines to predict the run-up of oil prices to over $140 in mid-2008. It would have been impossible for Pacific Ethanol to predict a rise in corn prices.

24/7 Wall St. looked at a number of companies which have been through major turnarounds in the last fifty years. Many are better off now than at any time in their histories.