The following quality assessment techniques are performed by BBL:
• Inspection during manufacture of materials and equipment
• Witnessing of the final manufacturing, type and reduced models testing, and equipment
  commissioning
• Conducting or witnessing nondestructive testing
• Inspecting equipment in use or in maintenance
• Auditing manufacturers’ quality system, process or product
• Subcontractors qualification or auditing
• Inspection of civil constructions and electromechanical assembly

Normally the following main mechanical, electrical and electronic equipment of the trains and fixed systems are submitted to quality evaluation, although other components may be included:
 

TRAINS
• Box car structure
• Cabin and box finishing sets and sub-sets
• Trucks
• Traction and electrical braking system
• Friction braking and non-skid systems
• Ancillary electrical systems
• Protection and automatic operations equipment
• ATC on board
• Communication devices

FIXED SYSTEMS
• Operational control center (OCC)
• Low, average and high tension equipment
• Communication system
• Electrical supply system and accessories
• Sign and control systems
• Ancillary systems and installation material
• Permanent track and accessories
• Station ancillary equipment
• Civil projects