Managing Subcontractors Across Multiple Construction Projects: What Can Go Wrong?

One Subcontractor. Five Projects. Five Different Experiences.

Imagine a subcontractor working across five construction projects for the same main contractor.

On one site, they're performing exceptionally well.

On another, they're falling behind programme.

A third project has raised concerns about workmanship.

Meanwhile, two other project teams are preparing to appoint them for additional work.

But does anyone have the complete picture?

In construction, it's common for the same subcontractors to work across several projects simultaneously.

For larger contractors, this can involve hundreds of suppliers operating across different sites, each with its own project team, programme and requirements.

The challenge isn't simply managing individual subcontractors.

It's understanding what's happening across the entire supply chain when those subcontractors are working in several places at once.

Why Managing Subcontractors Across Multiple Projects Is Difficult

Each construction project operates within its own environment.

There are different site managers, commercial teams, project requirements, deadlines and working arrangements.

Even when two projects use the same subcontractor, their experiences can be completely different.

One project team might have an excellent working relationship with a supplier.

Another might be experiencing repeated delays.

A third might have identified concerns that haven't been communicated to the wider business.

When supplier information is managed separately by each project, important details can remain isolated.

This makes it difficult for contractors to understand supplier performance, manage risk and make consistent appointment decisions across their organisation.

1. Different Projects May Have Different Approval Requirements

A subcontractor might be approved to work for a contractor, but that doesn't necessarily mean they're suitable for every project.

Different projects can have different requirements depending on the type of work, client expectations and associated risks.

For example, one project might require additional evidence of specialist competence.

Another may have specific insurance requirements.

A third could require further assessments before a supplier is permitted to undertake particular activities.

This creates an important distinction between general supplier approval and project-specific suitability.

A supplier may meet the organisation's standard pre-qualification requirements but still need further checks before being appointed to a particular project.

Without a clear process, project teams may assume that a supplier's general approval automatically covers everything.

That assumption can create unnecessary risk.

2. Supplier Performance Can Vary Between Sites

A subcontractor's performance on one project doesn't always reflect their performance elsewhere.

Different projects have different levels of complexity, resource demands and management arrangements.

A supplier might deliver excellent work on a straightforward project but struggle when faced with a more demanding programme.

Alternatively, a supplier experiencing difficulties on one site may be performing well on several others.

This is why project-level assessments are valuable.

They allow contractors to understand how suppliers are performing under different circumstances.

For example, project teams might assess:

• Quality of workmanship
• Programme performance
• Health and safety
• Communication and coordination
• Commercial management
• Responsiveness to identified issues

When these assessments are recorded consistently, they can provide a more complete picture of supplier performance across the organisation.

3. Resource Conflicts Can Affect Multiple Projects

One of the biggest challenges when using the same subcontractor across several projects is resource availability.

Imagine a mechanical subcontractor working on three sites.

Each project manager has been assured that sufficient labour will be available to meet their programme.

However, one project falls behind and requires additional resources.

The subcontractor moves operatives from another site to recover the programme.

That second project then begins experiencing delays.

Before long, a resource problem on one project has affected several others.

This can be particularly challenging where specialist labour, equipment or materials are in limited supply.

Contractors therefore need to consider a supplier's wider commitments when assessing their capacity to undertake additional work.

A subcontractor may be capable of delivering the work in principle but lack the resources to meet several competing programmes simultaneously.

4. The Same Supplier Can Be Assessed Repeatedly

Another common challenge is duplicated administration.

A subcontractor might already have completed a detailed Pre-Qualification Questionnaire (PQQ) for the main contractor.

However, when they're considered for another project, a different team may request the same information again.

This can include insurance certificates, accreditations, company information, policies and supporting documentation.

For suppliers working across several projects, responding to repeated requests can become time-consuming.

For contractors, it creates additional work reviewing information that may already have been assessed elsewhere in the business.

A more efficient approach is to maintain a central supplier record for information that applies across the organisation, while collecting additional information where individual projects have specific requirements.

This reduces unnecessary duplication without removing important project-level checks.

5. Important Information Doesn't Always Reach Other Project Teams

Consider a subcontractor working on a project where several quality issues have been identified.

The site team records the problems and works with the supplier to resolve them.

However, the information remains within that project's records.

A few weeks later, another project team begins preparing a tender list.

The same subcontractor is included because they're approved and have previously worked for the business.

Nobody involved in the new appointment is aware of the recent quality concerns.

This doesn't necessarily mean the supplier should be excluded.

But the information could be relevant when assessing their suitability for further work.

Without effective communication between projects, contractors risk making decisions based on an incomplete understanding of supplier performance.

6. Supplier Documents Can Change During a Project

Supplier compliance isn't something that only matters at the point of appointment.

Documents and circumstances can change while work is ongoing.

For example:

• Insurance certificates may expire
• Accreditations may require renewal
• Company details may change
• Relevant qualifications may need updating
• Additional project requirements may arise

If a subcontractor is working across several projects, a change to their information may affect more than one project team.

This creates a coordination challenge.

Who is responsible for identifying the change?

Which projects need to be informed?

Does the change affect the supplier's ability to continue particular work?

A central supplier record can help reduce the risk of different project teams working from inconsistent information.

However, the implications of any change still need to be assessed against the requirements of each affected project.

7. Inconsistent Assessments Make Comparisons Difficult

Even when project teams assess subcontractor performance, the results aren't always comparable.

One project manager might rate a supplier as excellent because they completed their work on time.

Another might focus primarily on quality.

A third might place greater emphasis on communication and cooperation.

Without agreed assessment criteria, the same supplier could receive very different ratings for reasons that aren't immediately clear.

Standardised assessment frameworks can help.

This doesn't mean every project must use identical criteria regardless of the work involved.

It means establishing consistent performance measures where appropriate, while allowing for project-specific requirements.

Clear scoring guidance and supporting evidence also make assessments more useful when reviewed by procurement teams.

8. Commercial Issues Can Extend Beyond One Project

Commercial performance is another area where information can become fragmented.

A subcontractor might have unresolved commercial issues on one project while tendering for additional work elsewhere.

These issues could include disputed variations, delayed information, incomplete documentation or difficulties agreeing final accounts.

Not every commercial disagreement indicates poor supplier performance.

However, recurring patterns may be worth understanding before further appointments are made.

For contractors, the objective should be to maintain appropriate visibility of relevant commercial issues without allowing isolated disagreements to unfairly influence decisions.

This requires accurate records and a balanced approach to assessment.

9. Project Teams May Be Making Decisions in Isolation

Perhaps the biggest challenge is that individual project teams are often focused on delivering their own work.

A site manager needs reliable subcontractors.

A commercial manager needs competitive tenders.

A project manager needs to meet programme milestones.

Each team has its own priorities.

But supplier decisions can affect the wider organisation.

A subcontractor appointed to one project may already be experiencing resource pressures elsewhere.

A supplier removed from one tender list may still be actively working on another site.

A strong performance record on several projects may not be visible to a new project team.

This is where a coordinated approach to supply chain management becomes valuable.

It allows individual projects to retain the flexibility they need while benefiting from information gathered across the wider business.

How Can Contractors Manage Subcontractors More Effectively Across Multiple Projects?

There are several practical steps construction businesses can take.

Maintain a Central Supplier Record

Keep core supplier information in one place, including company details, relevant documentation, assessments and approval status.

This reduces the need for different project teams to maintain separate versions of the same information.

Separate General Approval From Project-Specific Requirements

Establish which requirements apply to the supplier across the organisation and which need to be assessed for individual projects.

A supplier being generally approved should not automatically mean they're suitable for every type of work.

Record Performance at Project Level

Capture feedback from the teams working directly with subcontractors.

Use consistent criteria where appropriate and ensure assessments reflect the circumstances of each project.

Review Capacity Before Making New Appointments

Consider whether a supplier has sufficient resources to deliver additional work alongside its existing commitments.

This may involve discussions about labour availability, specialist equipment, programme requirements and current workload.

Share Relevant Information Between Teams

Make sure procurement and project teams can access appropriate supplier performance information when making appointment decisions.

The objective is to improve visibility, not to prevent suppliers from being fairly considered for future work.

Review Suppliers Across the Organisation

Periodically look at supplier information across multiple projects.

This can help identify recurring strengths, common problems and areas where further engagement may be needed.

Why Project-Level Assessments Matter

A central supplier record is valuable, but it doesn't tell the whole story.

Construction suppliers work in different environments and their performance can vary between projects.

Project-level assessments help capture those differences.

They provide context around how a subcontractor performed on a particular job, rather than reducing their entire relationship with the contractor to one overall rating.

Over time, these assessments can help build a more complete picture.

For example, a supplier might consistently perform well on smaller projects but experience difficulties on larger, more complex schemes.

Another might demonstrate particularly strong performance on technically demanding work.

This information can be useful when selecting suppliers for future projects.

The goal isn't simply to identify which subcontractors are good or bad.

It's to understand where suppliers perform well, where challenges arise and which opportunities are appropriate for them.

How Liaison Mobilize Can Help

Liaison's Mobilize platform helps construction businesses manage supplier information, assessments and compliance across their supply chain.

Core supplier information can be maintained centrally, reducing the need for different project teams to manage separate records.

Mobilize also supports project-level supplier assessments, allowing organisations to record performance against relevant criteria.

This helps build a wider understanding of supplier performance across different projects while retaining the context of individual assessments.

Combined with PQQ management, supplier compliance information and tender management capabilities, Mobilize provides a more coordinated approach to managing subcontractors throughout the supplier relationship.

Rather than information remaining within individual project teams, it can contribute to a wider view of the supply chain.

Conclusion

Managing subcontractors across multiple construction projects creates challenges that aren't always visible when each project is considered separately.

A supplier might be performing well on one site while experiencing difficulties on another.

Different projects may have different approval requirements.

Resource commitments can overlap.

Important performance information can remain isolated within individual teams.

And the same supplier may be repeatedly asked to provide information that already exists elsewhere in the organisation.

The solution isn't to remove project-level decision-making.

It's to give those decisions better information.

By combining central supplier records with project-specific assessments, consistent performance measures and better communication, construction businesses can gain a clearer understanding of the subcontractors working across their projects.

Because knowing that a supplier is approved is useful.

Knowing how they're performing across your entire business is even better.