FORM 10-K

33 or inflation, (c) there is a change in engineering efforts required during the development stage of the contract or (d) we are unable to meet contract milestones. At the outset of each contract, we estimate the initial profit booking rate. The initial profit booking rate of each contract considers risks surrounding the ability to achieve the technical requirements (for example, a newly-developed product versus a mature product), schedule (for example, the number and type of milestone events), and costs by contract requirements in the initial estimated costs at completion. Profit booking rates may increase during the performance of the contract if we successfully retire risks surrounding the technical, schedule, and costs aspects of the contract. Likewise, the profit booking rate may decrease if we are not successful in retiring the risks; and, as a result, our estimated costs at completion increase. All of the estimates are subject to change during the performance of the contract and, therefore, may affect the profit booking rate. When adjustments are required, any changes from prior estimates are recognized using the cumulative catch-up method with the impact of the change from inception-to-date recorded in the current period. The following table sets forth the aggregate gross amount of all program profit adjustments that are included within segment profit for the three years ended December 30, 2017: (In millions) 2017 2016 2015 Gross favorable $ 92 $ 106 $ 111 Gross unfavorable (87) (23) (33) Net adjustments $ 5 $ 83 $ 78 Goodwill We evaluate the recoverability of goodwill annually in the fourth quarter or more frequently if events or changes in circumstances, such as declines in sales, earnings or cash flows, or material adverse changes in the business climate, indicate that the carrying value of a reporting unit might be impaired. The reporting unit represents the operating segment unless discrete financial information is prepared and reviewed by segment management for businesses one level below that operating segment, in which case such component is the reporting unit. In certain instances, we have aggregated components of an operating segment into a single reporting unit based on similar economic characteristics. We calculate the fair value of each reporting unit, primarily using discounted cash flows. These cash flows incorporate assumptions for short- and long-term revenue growth rates, operating margins and discount rates that represent our best estimates of current and forecasted market conditions, cost structure, anticipated net cost reductions, and the implied rate of return that we believe a market participant would require for an investment in a business having similar risks and business characteristics to the reporting unit being assessed. The revenue growth rates and operating margins used in our discounted cash flow analysis are based on our strategic plans and long-range planning forecasts. The long-term growth rate we use to determine the terminal value of the business is based on our assessment of its minimum expected terminal growth rate, as well as its past historical growth and broader economic considerations such as gross domestic product, inflation and the maturity of the markets we serve. We utilize a weighted-average cost of capital in our impairment analysis that makes assumptions about the capital structure that we believe a market participant would make and include a risk premium based on an assessment of risks related to the projected cash flows of each reporting unit. We believe this approach yields a discount rate that is consistent with an implied rate of return that an independent investor or market participant would require for an investment in a company having similar risks and business characteristics to the reporting unit being assessed. If the reporting unit’s estimated fair value exceeds its carrying value, there is no impairment, and no further analysis is performed. Otherwise, the amount of the impairment is determined by comparing the carrying amount of the reporting unit’s goodwill to the implied fair value of that goodwill. The implied fair value of goodwill is determined by assigning a fair value to all of the reporting unit’s assets and liabilities, including any unrecognized intangible assets, as if the reporting unit had been acquired in a business combination. If the carrying amount of the goodwill exceeds the implied fair value, an impairment loss is recognized in an amount equal to that excess. Based on our annual impairment review, the fair value of all of our reporting units exceeded their carrying values, and we do not believe that there is a reasonable possibility that any units might fail the initial step of the impairment test in the foreseeable future.