An NEC activity schedule is the Contractor's own priced list of the work, used in Options A and C. Each line is a lump sum, and the lump sums add up to the total of the Prices. Under Option A it decides what the Contractor is paid and when; under Option C it only sets the target.
A well-built schedule makes payment, programme updates and compensation events simpler. A poor one causes arguments at every assessment. This guide covers NEC4 ECC, with NEC3 numbers noted, and sits in the NEC main Options section.
What the contract says about it
| Rule | NEC4 ECC | NEC3 ECC |
|---|---|---|
| Show how activities relate to operations on each programme submitted | 31.4 | 31.4 |
| Its content isn't Scope or Site Information | 55.1 (A), 55.2 (C) | 54.1 |
| If activities don't relate to the Scope, the Contractor corrects the schedule | 55.1 (A) | No equivalent wording |
| When to submit a revision | 55.3 (A) | 54.2 |
| Reasons for not accepting a revision | 55.4 (A) | 54.3 |
| Changed Prices for compensation events appear as changes to it | 63.14 | 63.12 |
The 55.1 point matters most. If the schedule leaves out work the Scope requires, the Contractor still has to do that work, for no extra money. Nor does anything listed in the schedule add to the Scope.
Building a schedule, step by step
- Start from the programme, not the estimate. Use programme operations, then group them into activities. It makes the 31.4 link easy to show.
- Define what "complete" means for each activity. "Foundations" is vague. "Foundations to grid A-F poured and struck" can be checked on site.
- Size activities for cash flow. Under Option A, an unfinished activity earns nothing. A rule of thumb many teams use is to keep activities short enough to finish within one or two assessment intervals. It's a choice, though, not a contract requirement.
- Allocate preliminaries deliberately. Site set-up and removal can be their own activities. Running costs need dividing sensibly, perhaps with a monthly "time-related" activity for each period.
- Allocate risk and overhead allowances sensibly. The total has to reflect the whole price, but a heavily front-loaded schedule invites challenge at tender.
- Consider grouping. The contract lets activities be grouped, with payment when the whole group finishes. Check how this affects cash flow. On termination, under 93.3, grouping is ignored.
An example of fixing a weak line
Illustrative figures for a fictional office job with four-weekly assessments:
| Weak | Better | |
|---|---|---|
| Line | Mechanical and electrical: £620,000 | Separate lines for first fix per floor, plant room, second fix per floor and commissioning |
| When paid | Possibly after 20 weeks, once everything is finished | Stage by stage, each within about four to eight weeks |
| What happens if there's a dispute about one floor? | The whole £620,000 is at stake | Only that floor's activity is affected |
| Fit with the programme | One bar, covering many operations | Links directly to operations |
Using the schedule during the job
- At each assessment (Option A): check which activities have finished, with no notified Defect whose correction would delay following work. Keep a dated list, signed off or agreed, rather than leaving it to memory.
- When the Contractor changes its method: under 55.3 it submits a revised schedule. The reasons for not accepting one under 55.4 are that it doesn't relate to the Accepted Programme, that changed Prices aren't reasonably spread across work still to come, or that the total has moved.
- When a compensation event is implemented: change the schedule, under 63.14. Add a new activity or change existing ones. Pick one convention for the whole job. See compensation events under Option A for a fuller discussion.
- On Option C jobs: keep the schedule current, even though it doesn't drive monthly payment. It's the target for the Contractor's share, and its total needs to be right at Completion.
What goes wrong
- Treating it as an estimate summary. Lines that follow trades rather than operations make the 31.4 link hard to show.
- Moving money between activities without a revision. That's outside the contract and will surface in an audit or dispute.
- Treating schedule line wording as part of the deal. Under 55.1, it doesn't change the Scope in either direction.
- Using lump sums as rates for compensation events. The assessment is based on Defined Cost, unless the parties agree otherwise, so don't assume you can scale up a line. The guide to the Prices explains why.
- Missing programme updates. If the programme moves and the schedule doesn't, the link in 31.4 breaks. Review them together, and read what the Accepted Programme is for more on how the two connect.
Related guides
- NEC Main Options: A to F Explained
- The Bill of Quantities Under NEC
- Target Cost and the Contractor's Share
- Pain/Gain Share Explained
- Option C vs Option E
- How to Choose an NEC Main Option
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