On any project with more than one work package, the biggest commercial risk is not always the change itself.
It is losing track of the change.
One team works from an old drawing. Another prices a revised instruction. Two packages include the same work. A change is implemented on site but never valued. A scope reduction is agreed in a meeting and disappears from the commercial record.
The result is predictable: cost and delay become difficult to separate, entitlement becomes harder to prove and the final account turns into an exercise in reconstruction.
Configuration control keeps the record straight.
It gives you a current, reliable position on:
- what the agreed scope is;
- which version of the information is current;
- what has changed from that position;
- who authorised the change;
- what the change affects;
- what has actually been implemented.
This is a core part of project controls for contractors. It is not an oversized process reserved for major infrastructure programmes. It is the commercial discipline of those programmes, right-sized for your business.
What configuration control means in practice
Configuration control means managing the agreed position and every authorised movement away from it.
That includes drawings, specifications, schedules, instructions, programmes, cost information and records of what was built. It is not just document management.
The question is not simply, “Which document is latest?”
You also need to know:
- whether the latest drawing has been accepted or merely issued for comment;
- whether it changes the agreed scope;
- which work packages and interfaces it affects;
- whether the change has been assessed for cost and time;
- whether anyone had authority to commit the resource;
- whether the built position matches the authorised position.
The record must connect the instruction, assessment, approval, implementation and final account. If those links are missing, the project team starts relying on memory, assumptions and scattered email chains.
Truth becomes harder to find.
The four-step change lifecycle
A workable change process has four steps:
- Identify the change.
- Assess the impact.
- Obtain approval.
- Implement and record the outcome.
Each step needs the right people and a clear record.
| Step | What you should do | Who should be involved | Record that should result |
|---|---|---|---|
| Identify | Compare the current information with the agreed scope. Capture instructions, revised drawings, omissions, additions and changes in sequence or access. | Site team, design team, planner, commercial team and package managers | Change notification or change register entry, with source information and date of awareness |
| Assess | Test direct cost, indirect cost, time, critical path, risk, resources and effects on other packages. State assumptions where the full position is not yet known. | Quantity surveyor, planner, site manager, design lead and affected package owners | Impact assessment linked to the programme, forecast and relevant documents |
| Approve | Confirm who has authority to accept the change and commit resource. Obtain the client or project manager’s contractual instruction where required. | Project manager, commercial lead, authorised director and client-side representatives | Written instruction, approval or decision with delegated authority confirmed |
| Implement and record | Deliver the revised scope. Update drawings, programme, forecast, cost records, testing information and as-built records. | Delivery team, document controller, planner, commercial team and commissioning team | Controlled revision, implementation record, updated forecast and linked valuation |
A change is not controlled because it appears in a meeting minute. It is controlled when the project can trace what happened from the original position to the implemented result.
An instructed change is not the same as a valued change
Contractors often lose money in the gap between instruction and valuation.
A change can be entirely legitimate and still remain unvalued for months if nobody captures it properly, assesses the full effect or links it to the forecast.
Under NEC4, compensation events provide the contractual mechanism for changing the Prices, Completion Date and, where relevant, Key Dates. The process is not complete because an instruction has been issued.
You still need to:
- identify the contractual event;
- notify it within the required period;
- assess cost and programme together;
- maintain the supporting records;
- track the event through quotation, decision and implementation.
Under the standard NEC4 ECC wording, contractor-notified compensation events normally carry an eight-week time bar from becoming aware that the event has happened. The assessment uses Defined Cost plus Fee, with cost and programme considered together.
Our guide to NEC4 compensation event management explains the notification and assessment process in more detail.
The practical point is simple: do not confuse an instruction with recovery. Capture the change early, protect the notice position and keep the valuation moving.
Identify change as a discipline, not by luck
The commercial team should not be the only group looking for change.
Site managers may receive a casual instruction. A design lead may spot that a revised drawing changes the installation sequence. A supervisor may identify a scope reduction that nobody has communicated to procurement. A planner may see a new access restriction affecting another package.
Brief your teams on what counts as a potential change. Make it easy to raise one.
Your process should cover:
- verbal instructions and site discussions;
- revised drawings issued without commentary;
- changes to specifications or schedules;
- omissions and scope reductions;
- changes to access, sequencing or working hours;
- late information;
- altered testing or commissioning requirements;
- changes that affect another package rather than your own.
Review potential changes every week. Link the review to the programme, commercial forecast and risk process.
This also connects directly to early notification. Under NEC4, an early warning identifies a matter that could affect cost, time, Key Dates or performance. It gives the project team an opportunity to mitigate the effect. It does not replace a compensation event notice.
Read the NEC4 early warnings process for the distinction and the practical sequence.
Assess the whole impact, not just your package
Package-by-package assessment misses the real effect of many changes.
A change to the mechanical package may affect builders’ work, access, temporary works, electrical services, testing and commissioning. A revised structure may alter follow-on activities and prolong another subcontractor’s attendance.
Interface effects are commonly overlooked because each package looks at its own instruction in isolation.
For every change, assess four areas.
Cost
Separate:
- direct labour, plant, materials and subcontract costs;
- indirect and disruption effects;
- time-related site and management costs;
- any reduction or omission from the original scope.
Time
Test the effect against the current programme. Identify affected activities, logic, float and the critical path.
Do not simply state that the change caused delay. Show how the sequence changed and whether planned Completion moved.
Risk
Ask what new exposure the change creates. It may introduce design uncertainty, procurement risk, access constraints, rework or additional testing.
Resources
Consider what the change does to labour, plant, supervision, subcontractors, temporary works and other workfronts.
If the full effect is not yet known, state the assumptions. A clear provisional assessment is more useful than a late report pretending to have certainty.
The cost forecast must then reflect the current position. The BHD cost control guide explains why movement needs to be identified before it becomes a final account surprise.
Approval is your responsibility too
The client has its own change process. You still need an internal one.
A site instruction may be validly issued but still exceed the authority of the person acting on your side. If your team commits labour, orders materials or changes sequence without internal approval, you may create a cost exposure before the commercial position has been checked.
Set simple delegated authority limits.
For example:
- site management can log and investigate a change;
- the project manager can approve limited operational action;
- the commercial lead must approve cost commitments above an agreed threshold;
- a director must approve significant scope, margin or programme exposure.
The system should not prevent sensible action. It should make responsibility clear.
Do not leave approval to memory. Record who approved what, when and on what information.
One controlled record and one current position
A smaller contractor does not need an elaborate system. You do need consistency.
A proportionate arrangement includes:
- one change register;
- one named owner for change control;
- one fixed weekly review slot;
- a rule that no change is implemented without being logged;
- one place where the current information lives;
- a reference linking instruction, assessment, approval and implementation;
- a monthly reconciliation against the cost forecast and programme.
Your document system or common data environment should make the current version clear. Do not allow multiple uncontrolled versions to circulate by email or sit in personal folders.
Version confusion creates a specific commercial problem: cost and delay become impossible to separate. By final account, the team is trying to establish which drawing was used, when the instruction arrived and whether the work was already included elsewhere.
That is too late.
Common failures and their consequences
The same weaknesses appear repeatedly:
- changes are implemented before they are logged;
- verbal instructions are acted on without written confirmation;
- several drawing versions remain in circulation;
- two packages price the same change;
- a change is valued on time but not cost, or cost but not time;
- the change register is not reconciled to the forecast;
- approval is treated as the client’s problem alone;
- interface effects are missed;
- the change history is reconstructed at final account.
The fix is not more reporting. It is a usable control process that connects site action, contract administration, programme, cost and records.
The coming posts in this project controls cluster will also cover earned value without the jargon and reporting burden that often surrounds it. The principle is straightforward: compare what you planned, what you have delivered and what it has cost. Configuration control provides the reliable baseline that makes that comparison meaningful.
Configuration control at handover
The record must remain accurate through handover.
The as-built position, testing and commissioning records, operation and maintenance information and final account should reflect the authorised scope. They should not reflect the last set of drawings someone happened to use.
Before handover, reconcile:
- approved changes against the final drawings;
- implemented work against the change register;
- testing and commissioning results against the revised scope;
- outstanding changes against the final forecast;
- the final account against the controlled record.
This is where early discipline pays off. You hand over a record you can explain, rather than a collection of documents assembled under pressure.
Frequently asked questions
What is configuration control?
Configuration control is the process of keeping a reliable record of the agreed scope, current information, authorised changes and implemented position. It covers drawings, specifications, instructions, programmes, cost information and handover records.
What is the difference between a change and a variation?
A change is any movement from the agreed scope, sequence, information or requirement. A variation is a contractual term used in some forms, particularly JCT, for an instructed change to the works.
Under NEC4, the contractual route is generally a compensation event. Always check the contract wording rather than relying on terminology alone.
Can I get paid for work I have already done without an instruction?
Do not assume so. Your position will depend on the contract, the authority of the person giving the direction, the records and whether the work falls within an established entitlement mechanism.
Record the direction, seek written confirmation, notify the potential change and obtain advice promptly. Retrospective recovery is harder than early administration.
How do I stop changes being missed?
Train site and commercial teams on what to look for, make changes easy to raise, review them weekly and link the change register to the programme and forecast.
Do not rely on the commercial team alone.
Who should own the change register?
One person should own its maintenance, usually the project controls or commercial lead. The whole delivery team must contribute. Site, planning, design, procurement and package managers all see different parts of the change picture.
What happens if two packages price the same change?
The change must be separated by scope and responsibility. Compare both assessments against the instruction, identify duplicated work and agree which package owns each element.
If you do not resolve it early, you risk double valuation, conflicting records and an inflated forecast.
Keep the record straight early
Projects go wrong. Instructions arrive late. Drawings change. Interfaces move.
The answer is not to describe the problem at final account stage. It is to identify the change early, assess the full effect, obtain authority and keep the record aligned with what is built.
Early rather than late. Truth rather than presentation. A usable plan rather than a descriptive report. Proportionate controls rather than oversized processes.
BHD Limited provides project controls, NEC contract administration, compensation event management and commercial support for contractors across the UK. BHD Commercial's team brings 25 years' experience across construction, defence and infrastructure. Our head office is at 66 Paul Street, London EC2A 4NA, with a regional office at 4-5 Victoria Square, Wolverhampton, WV1 1LD.
If you want a straight view of your current change process, request the free Commercial Health Check. We will review where changes are being captured, where the record is exposed and what you can act on next.