Short answer: when a change order (called a variation in the UK, the Gulf, India and Australia) lands, log it as a task the same day, trace every task that depends on the affected work, set a date by which the client must decide, and only then move the dates and tell the crew. The extra work is rarely the problem. The problem is the linked tasks nobody updated.
Why do change orders cause so many delays?
Because waiting usually costs more time than the work. PlanRadar's Construction Survey Report 2026, based on 1,728 project professionals in 14 countries across Europe, the Middle East and Asia-Pacific (including the UAE, Saudi Arabia and Singapore), found that delayed approvals are the biggest pain point in managing changes. Nearly three in four respondents said approvals often arrive after the agreed time, and one in four said delayed approvals typically add more than a month to the timeline (PlanRadar, Apr 2026).
The same survey found that nearly 8 in 10 respondents keep most project records spread across email, calls, text messages and verbal instructions (PlanRadar webinar recap, Jun 2026).
Process matters too. In FMI's 2026 Project Management Study of US contractors, firms with a highly consistent change order process met or beat their schedules about 80% of the time, against about 65% for less consistent firms (FMI, Q1 2026).
What does a change order look like on a field job?
Small field-service jobs change all the time:
- AC installation: the client adds a second indoor unit, so the pipe run, the electrical work and the commissioning visit all move.
- Solar: the survey finds a roof repair is needed before the panels go up, so the install date and the grid-connection step shift.
- Fit-out or construction: the client moves a wall, so partitions, electrical first fix and painting are re-sequenced.
Each change touches several tasks, often owned by different people.
How do you update the schedule when scope changes?
- Log the change the day it is raised. Add it to the plan as a task with an owner, a short description and who asked for it.
- Trace the linked tasks. Start from the task the change affects and follow its dependencies forward. List every task and milestone downstream, such as inspection, commissioning or handover.
- Set a decision date. Add a milestone for the date the client must approve, based on when the next dependent task has to start.
- Decide what happens while you wait. Pause only the affected tasks, keep unaffected work moving, and avoid starting changed work without written approval.
- Move the dates once approved. Shift the changed task and its dependent tasks, check whether any milestone slips, and reassign work if a crew or subcontractor is now double-booked.
- Tell the crew from the plan. Share the updated schedule, not a separate message, so field and office see the same dates.
| Change type | Example | What to update |
|---|---|---|
| Added scope | Extra AC unit | New tasks, commissioning date, handover milestone |
| Changed condition | Roof repair before solar install | Install start, crew booking, grid-connection step |
| Re-sequenced work | Wall moved in a fit-out | Trade order, subcontractor dates |
| Material change | Different panel or unit model | Order-by date, delivery, install start |
If a change brings a new part with a long delivery time, set an order-by date as in our long-lead items guide. If it moves a trade, check the handoffs described in our subcontractor scheduling guide.
What mistakes make change orders worse?
- Agreeing the cost but not the dates. The crew finds out on site.
- Moving one task, not its chain. If you shift the install but not the inspection booking, the schedule lies.
- No decision date. Open-ended waiting can last weeks.
- Records scattered across chats. When a dispute comes later, nobody can show when the change was asked for or approved.
A schedule won't make a client decide faster, but it shows early, in dates, what waiting will cost.
Where Zace fits
Zace is a project and task tracker for field service jobs and the internal tasks around them. You can lay a job out as a Gantt chart, see which tasks depend on each other in the timeline view, move tasks on the timeline, mark milestones such as approval and handover, and assign tasks with a priority. The same plan works on the web, Android and iOS, so the office and the crew see one version. Zace is not a change-order approval, costing or document system, so keep approvals and costs in your usual contract process. For a weekly view of the next few weeks, see our 3-week lookahead guide.
Frequently asked questions
What is the difference between a change order and a variation?
Both mean an approved change to the agreed scope, time or cost. "Change order" is the usual US term; "variation" is used in the UK, the Gulf, India and Australia.
Should I start changed work before the change order is approved?
Usually not. Get written approval first. If you must start, record who instructed it and when.
How do I show a client the schedule impact of a change?
Show the tasks and milestones that move, with old and new dates. A Gantt chart with linked tasks makes this easy to see.
Sources (all linked inline): PlanRadar Construction Survey Report 2026 "Managing Project Changes in the Age of AI" (published 21 Apr 2026); PlanRadar webinar recap (30 Jun 2026); FMI 2026 Project Management Study, Part 2 (Q1 2026).