This excerpt taken from the GM DEF 14A filed Apr 27, 2007.
Performance Criteria. In determining the performance criteria applicable to any award under the Plan, the Committee may use one or more of the following business criteria: asset turnover, cash flow, contribution margin, cost objectives, cost reductions, earnings per share, economic value added, increase in customer base, inventory turnover, market price appreciation of the Common Stock, market share, net income, net income margin, operating profit margin, pre-tax income, productivity, profit margin, quality, return on assets, return on net assets, return on capital, return on equity, revenue, revenue growth, TSR, and/or warranty. The business criteria may be expressed in absolute terms or relative to the performance of other companies or to an index. If any event occurs during a performance period that requires changes to preserve the incentive features of this Plan, the Committee may make appropriate adjustments.