Table of Contents customer contracts, which may include unique contract terms, to determine whether revenue should be recognized at a point in time or over time as work progresses. In addition, for contracts where management determines revenue should be recognized over time as work progresses, management must estimate both total expected project costs and expected gross margin, including evaluating customer change orders, for all uncompleted contracts to determine the appropriate amount of revenue to recognize. Given the high degree of management judgment involved in evaluating project estimates and estimating the amount of revenue to recognize, the audit effort required to evaluate management’s judgments in determining revenue recognition for the Company’s contracts with infrastructure solutions customers was extensive and required a high degree of auditor judgment. Our audit procedures related to Infrastructure Solutions customer contracts included the following: /s/ GRANT THORNTON LLP We have served as the Company’s auditor since 2020. Dallas, Texas April 23, 2021 40 • We tested the effectiveness of internal controls over management’s review of customer contracts and change orders, to determine whether revenue should be recognized at a point in time or over time as work progresses. • We tested the effectiveness of internal controls over management’s estimation of the amount of revenue to recognize for customer contracts where revenue is recognized over time as work progresses. • We examined a sample of customer contracts to determine if management’s conclusions with respect to contract terms and revenue recognition appeared appropriate in the circumstances. • We evaluated the accuracy of estimates made by management in prior periods by comparing previous estimates to actual results. • We tested a sample of customer contracts for which management concluded that it was appropriate to recognize revenue over time as work progressed by evaluating key inputs and assumptions which impacted the amount of revenue recognized for each contract tested. The key inputs and assumptions included: ◦ The accumulation of historical costs incurred for the project, ◦ Management’s estimate of the total expected costs for the entire project, including costs yet to be incurred to complete the project, and ◦ Management’s estimate of the total expected gross margin to be realized upon completion of the project.