Operating segments are defined as components of an enterprise about which separate financial information is available that is evaluated regularly by the enterprise’s chief operating decision maker ("CODM"), or decision making group, in deciding how to allocate resources and in assessing performance. Our Chief Executive Officer is our CODM.

We measure the performance of our operating segments based upon operating segment revenue and operating segment contribution. Operating segment contribution includes segment revenue and expenses incurred directly by the segment, including material costs, service costs, research and development and selling, marketing, and administrative expenses. We do not allocate certain expenses, which include the majority of general and administrative expenses, facilities and communication expenses, purchasing expenses, manufacturing support and logistic expenses, depreciation and amortization, amortization of capitalized software development costs, stock-based compensation, and special charges such as restructuring costs when calculating operating segment contribution. These expenses are included in the unallocated expenses section of the table presented below. Revenue from transactions between our operating segments is not material.

Revenue adjustments represent revenue of acquired companies which is included within segment revenue reviewed by the CODM, but not recognizable within GAAP revenue.  These adjustments primarily relate to the acquisition-date excess of the historical carrying value over the fair value of acquired companies’ future maintenance and service performance obligations. As the obligations are satisfied, we report our segment revenue using the historical carrying values of these obligations, which we believe better reflects our ongoing maintenance and service revenue streams, whereas GAAP revenue is reported using the obligations’ acquisition-date fair values.