Supplier Ratings Methodology
This document sets out how SYNE constructs, weights, scores, and governs a Supplier Rating for suppliers, vendors and distributors. It covers scope, data sources, the full criteria framework, grade assignment, governance, review cycle, and appeals.
Twelve sections, start to finish.
Scope & Applicability
Who is eligible to be rated, and how a rating is commissioned.
02Data Sources & Collection
Financial records, site audits, and licensed third-party data.
03Criteria Framework
80 criteria across financial, compliance, environmental and continuity risk.
04Weighting & Scoring Methodology
How individual criterion scores combine into one composite score.
05Data Quality Adjustment
Why a score needs verified evidence to reach the top grade bands.
06Controversies, Market Intelligence & Modern Slavery Screening
How adverse events, market signals and forced labor risk are tracked.
07Continuous Monitoring
Ongoing surveillance between scheduled review cycles.
08Grade Assignment & Rating Scale
How the composite score maps to the shared AAA–D scale.
09Mapping to the SYNE Index
How this rating becomes a position on the two-axis Index.
10Governance & Independence
Who signs off on a rating, and how conflicts are managed.
11Review Cycle, Triggers & Appeals
When ratings are revisited, and how to challenge one.
12Limitations & Version History
What this rating does not do, and how the methodology has changed.
Who and what this methodology rates.
This methodology applies to suppliers, vendors, distributors and other counterparties in a buyer's supply chain, across any sector and any of SYNE's 71 licensed jurisdictions. It does not apply to the buyer or procuring organisation itself, which would instead fall under the ESG or Sustainability Ratings Methodology depending on its listing status.
A supplier becomes eligible for a Supplier Rating once it has submitted a completed onboarding disclosure questionnaire, or has been nominated for rating by a buyer commissioning panel-wide coverage. Ratings can be commissioned by the supplier itself, by a buyer as part of a panel programme, or jointly.
At a glance
- Applies to
- Suppliers, vendors, distributors & supply chain counterparties
- Minimum eligibility
- Completed onboarding disclosure questionnaire, or buyer nomination
- Commissioned by
- The supplier, a buyer running a panel programme, or jointly
- Geographic scope
- Any of SYNE's 71 licensed jurisdictions
- Excludes
- The buyer or procuring organisation itself - see the ESG or Sustainability Ratings Methodology
Where the underlying evidence comes from.
Every Supplier Rating draws on financial records, compliance documentation, and independent site verification, weighted toward independently verifiable evidence wherever possible.
Financial & corporate records
Audited financial statements, credit bureau data, and beneficial ownership registries.
Site audits & desktop verification
On-site audits and desktop document verification of labor, safety and environmental compliance records.
Licensed & buyer-submitted data
ESG risk and supply chain mapping data licensed through SYNE Data, and Nth-tier disclosures submitted by the buyer.
80 weighted criteria across four dimensions.
Each criterion is scored on a normalised 0–100 basis by a lead analyst, using a documented scoring rubric aligned to ISO 20400, SA8000, the UN Guiding Principles on Business and Human Rights, and ILO Core Conventions, before dimension and composite scores are calculated.
Financial Stability & Viability
Whether a supplier can remain a going concern for the life of the contract.
- Credit Rating & Financial Ratio Analysis
- Liquidity & Cash Flow Assessment
- Ownership & Ultimate Beneficial Owner Screening
- Insolvency & Bankruptcy Risk Indicators
Compliance & Labor Standards
Legal, ethical and labor practice compliance across the supplier's operations.
- Modern Slavery & Forced Labor Screening
- Wage & Working Hours Compliance
- Health & Safety Management Systems
- Anti-Bribery & Corruption Controls
Environmental & Sustainability Practices
Emissions, permitting and resource management quality across supplier operations.
- GHG Emissions Disclosure & Scope 3 Data Quality
- Environmental Permit Compliance
- Waste & Hazardous Materials Management
- Environmental Management System Certification (ISO 14001)
Business Continuity & Resilience
How exposed a supplier is to disruption, and how prepared it is to recover.
- Single-Source & Concentration Risk
- Disaster Recovery & Business Continuity Planning
- Nth-Tier Sub-Supplier Visibility
- Geopolitical & Climate Exposure
How 80 individual scores become one number.
Each of the 80 criteria carries a base weight set by supplier-category materiality mapping, reviewed annually against evolving compliance regimes. Criterion scores are aggregated into a dimension score using the weighted average of that dimension's criteria, and dimension scores are then combined into the composite score using the dimension weights shown in Section 03.
Supplier-category materiality mapping
Criterion weights are adjusted by category - for example, labor compliance criteria carry more weight for a manufacturing supplier than for a software vendor.
Weighted average, not simple average
No criterion is dropped for missing data; a missing criterion is scored as zero unless a documented exemption applies, preventing silent grade inflation.
Non-compensatory floors
An unresolved modern slavery or forced labor finding in the Compliance & Labor Standards dimension caps the composite score, regardless of financial strength elsewhere.
A strong score on self-reported data isn't a strong rating.
Every criterion score carries a parallel data quality flag - Assured, Disclosed, or Estimated - based on the strength of its underlying evidence. A composite score cannot reach the AAA or AA band unless at least 80% of its criteria carry an Assured or Disclosed data quality flag, and no more than 10% are flagged Estimated.
Independently verified
Backed by an on-site audit, independently verifiable public record, or third-party certification.
Supplier-disclosed, unassured
Reported directly by the supplier through the onboarding questionnaire, without independent verification.
Modelled or inferred
Estimated using sector proxies or country-level compliance risk data where direct supplier data isn't available.
How adverse events, market signals and forced labor risk feed into Compliance scoring.
Controversy and market intelligence data is sourced systematically from SYNE's Market & Trade Intelligence coverage, rather than relying on the supplier's own disclosure of adverse events. Modern slavery and forced labor risk is screened using dedicated indices and watchlists, aligned to the UK Modern Slavery Act and the ILO Forced Labour Convention, rather than supplier self-attestation alone.
Systematic adverse media monitoring
Every rated supplier is monitored on the same basis, regardless of whether it has appeared in the news.
Dedicated forced labor screening
Screened against recognised modern slavery, forced labor and human trafficking indices, not supplier self-attestation alone.
Sector & country risk benchmarking
Market intelligence positions a supplier's controversy and compliance record against comparable category and country peers.
What happens between scheduled review cycles.
A rating is not frozen for a full year between reviews. Continuous monitoring tracks signals that could affect a supplier's score in real time, feeding into the interim review triggers described in Section 11.
Controversy & event alerts
New adverse events, sanctions listings, or modern slavery flags are surfaced as they're identified, not held until the next scheduled review.
Quarterly data refresh
Financial, credit and country-risk data feeding the Financial Stability and Environmental dimensions refresh at least quarterly.
Threshold-based escalation
A monitoring signal that crosses a defined materiality threshold is escalated to the Rating Committee for an interim review decision.
How the composite score becomes a letter grade.
The composite score, after data quality adjustment, is mapped to the six-tier AAA–D scale shared across every SYNE product.
Requires Assured data quality on at least 80% of criteria, per Section 05.
Requires Assured or Disclosed data quality on at least 80% of criteria.
Material gaps identified in compliance or continuity, being actively addressed.
Significant improvement needed in financials, compliance or continuity planning.
Fundamental gaps in financial viability or compliance controls.
No material evidence of financial viability or compliance capability.
How this rating becomes a point on the Index.
The SYNE Index plots every rating on two axes: Standards Alignment and Data Quality & Assurance. For Supplier Ratings, the Standards Alignment axis is derived from the weighted average of the Compliance & Labor Standards and Environmental & Sustainability Practices dimension scores; the Data Quality & Assurance axis is derived from the Financial Stability & Viability dimension's verification depth combined with the data quality flags described in Section 05. See the SYNE Index Methodology for the full cross-product calculation.
Front Runners
Strong compliance and environmental practice, backed by independently verified financial and audit data.
Rising Stars
Strong compliance standards, with financial and audit verification still maturing.
Emerging Stars
Well-verified financial position, but with narrower compliance or environmental practice coverage.
Backmarkers
Limited compliance and environmental practice, with unresolved financial or verification gaps.
Who signs off on a rating, and how conflicts are managed.
Independent Rating Committee
A committee separate from the lead analyst reviews and approves every rating before publication.
No pay-for-rating influence
Fees are agreed before an engagement begins and have no bearing on the rating outcome; analysts hold no financial interest in rated companies.
Factual accuracy review only
Rated companies may review a draft rating once, strictly for factual accuracy - not to negotiate the score.
When a rating is revisited, and how to challenge one.
Annual review
Every rating is fully reassessed at least once every 12 months, aligned to the company's own reporting cycle where possible.
Interim review triggers
A material controversy, restatement, M&A event, or leadership change can trigger an interim review ahead of the next scheduled cycle.
Factual accuracy window
Rated companies have 10 business days from draft delivery to raise a factual accuracy challenge before a rating is finalised.
What this rating does not do.
A Supplier Rating is an opinion of a supplier's financial, compliance and continuity resilience as of the rating date - it is not a guarantee of future performance, an endorsement of product quality, or an investment recommendation. It relies on data provided by, or obtained about, the rated supplier and cannot detect fraud or concealment that no available evidence would reveal.
| Version | Effective date | Summary of changes |
|---|---|---|
| v1.1 | Jul 2026 | Added Controversies, Market Intelligence & Modern Slavery Screening and Continuous Monitoring sections. |
| v1.0 | Jan 2026 | Initial publication of the Supplier Ratings Methodology. |
This document is available in full, including prior versions, on request as part of SYNE's regulatory disclosure pack. For questions about how a specific criterion is scored, contact SYNE's methodology team.
See how this methodology applies to your supplier panel.
Talk to our team about commissioning Supplier Ratings, or request panel-wide onboarding support.