In the oil and gas service industry, ensuring that purchased services and service-related products (SRPs) meet all required specifications is critical to maintaining quality, safety, and operational integrity. To achieve this, companies must adopt a structured supplier management process and ensure transparent communication of purchasing requirements. 

This guide outlines the key purchasing information and supplier requirements that must be documented and communicated, along with the verification activities needed to ensure compliance with API Spec Q2 and other international quality standards. 

  1. Documenting Purchasing Information

When procuring services or SRPs, organizations must ensure that all expectations are clearly defined and documented to maintain consistent supplier quality performance. 

a) Acceptance Criteria for Services and SRPs

The purchasing documentation must specify clear acceptance criteria, including: 

  • Performance benchmarks and measurable targets, 
  • Dimensional tolerances, 
  • Test results and validation reports, 
  • Delivery and documentation requirements. 

Clearly defined acceptance standards reduce ambiguity, ensuring suppliers understand the minimum quality requirements to be met. 

b) Approval Requirements for Supplier Procedures, Processes, or Equipment

When dealing with critical service operations, companies must define if prior approval is required for: 

  • Supplier-specific procedures (e.g., welding, heat treatment, cleaning), 
  • Operational processes (e.g., inspection, testing, calibration), 
  • Equipment or tools used to deliver services. 

This is vital for services that impact product conformity or safety, especially in API Q2-certified operations. 

c) Technical Specifications and Data

All technical documents must include the applicable version of: 

  • Engineering drawings and process requirements, 
  • Inspection and testing instructions, 
  • Specifications aligned with API and ISO standards, 
  • Regulatory and contractual data. 

This ensures suppliers use the most updated specifications, reducing the risk of nonconformities caused by outdated information. 

d) Qualification Requirements for Supplier Personnel

For specialized services such as non-destructive testing (NDT) or equipment calibration, suppliers must assign qualified and certified personnel.
The purchasing documentation should define: 

  • Required certifications (e.g., ASNT Level II, ISO 9712), 
  • Experience and training prerequisites, 
  • Competency evaluation records. 

e) Quality Management System (QMS) Requirements

Suppliers must demonstrate compliance with a recognized Quality Management System, such as: 

  • ISO 9001, 
  • API Spec Q1 or Q2 (for critical service providers), 
  • Internal customer-specific quality requirements. 

Evidence such as certificates, quality manuals, and QMS audit reports should be reviewed during supplier evaluation and monitoring. 

  1. Verification of Purchased Services and SRPs

The responsibility of the service company extends beyond issuing a purchase order. To ensure supplier compliance, the organization must establish a documented verification process aligned with API Q2 Clause 4.5. 

a) Defining Verification Criteria

Verification procedures must clearly define: 

  • Inspection and testing methods, 
  • Responsible personnel and timelines, 
  • Acceptance or rejection criteria, 
  • Verification location (supplier site or upon receipt). 

b) Verification Activities and Record Keeping

Verification activities can include: 

  • Reviewing Certificates of Conformity (CoC), 
  • Conducting dimensional inspections and functional tests, 
  • Witnessing supplier tests or site audits, 
  • Maintaining nonconformance and corrective action records. 

All verification activities should be recorded in the Quality Management System for traceability and compliance evidence. 

c) Ensuring Conformity of Outsourced Services

When services are outsourced, the company retains full responsibility for ensuring conformity. Key actions include: 

  • Establishing clear supplier contracts and acceptance gates, 
  • Conducting periodic supplier audits and requalification, 
  • Monitoring supplier KPIs such as on-time delivery, nonconformance rate, and service performance. 

By documenting comprehensive purchasing information and implementing robust supplier verification practices, companies can ensure that suppliers consistently meet technical, legal, and safety standards. 

A disciplined approach aligned with API Spec Q2 requirements helps: 

  • Strengthen supply chain integrity, 
  • Enhance customer satisfaction, 
  • Reduce nonconformities and operational disruptions, 
  • Improve audit readiness and regulatory compliance. 

Ultimately, effective supplier quality management safeguards product reliability and reinforces the organization’s commitment to excellence in the oil and gas service industry.