Change orders are by its very nature waste in a process. Understanding why the change orders are needed and finding ways to minimize these efforts. In addition, many times Civil Engineers work on projects that have a fixed budgets. Yet many times, the hours required to complete the project exceed the budget. Every engineering firm I have worked with had some committee working to address their non-billable hours, but few focused their efforts on process improvement.
Finally, even the process of job estimating can be improved through Green Belt/Black Belt training. One company who did extensive real estate development projects learned enough about their processes so that they were able to complete their estimates in under ½ hour.