Segment Information

3 Months Ended

Mar. 31, 2019

SEGMENT INFORMATION

We have five operating segments, Aerospace, Combat Systems, Information Technology, Mission Systems and Marine Systems. We organize our segments in accordance with the nature of products and services offered. We measure each segment’s profitability based on operating earnings. As a result, we do not allocate net interest, other income and expense items, and income taxes to our segments.

Summary financial information for each of our segments follows:



	Revenue				Operating Earnings
Three Months Ended	March 31, 2019		April 1, 2018		March 31, 2019			April 1, 2018
Aerospace	$	2,240	$	1,825	$	328		$	346
Combat Systems	1,636		1,440		206			224
Information Technology	2,169		1,138		156			101
Mission Systems	1,158		1,098		148			146
Marine Systems	2,058		2,034		180			184
Corporate	—		—		(4		)	7
Total	$	9,261	$	7,535	$	1,014		$	1,008

Corporate operating results have two primary components: pension and other post-retirement benefit income, and stock option expense. We are required to report the non-service cost components of pension and other post-retirement benefit cost (e.g., interest cost) in other income (expense) in the Consolidated Statement of Earnings. As described in Note O, in our defense segments, pension and other post-retirement benefit costs are recoverable contract costs. Therefore, the non-service cost components are included in the operating results of these segments, but an offset is reported in Corporate.