T&C is executed in progressive stages, usually covering the following sequence: 1. FAT (Factory Acceptance Test)

FAT is the first formal stage of testing and is conducted at the manufacturer’s premises. The primary objective is to verify that the equipment or system complies with the approved design specifications and functional requirements before being delivered to site. This includes hardware inspection, software testing, control logic validation, and power supply checks. FAT helps identify any non-conformities early and avoids transporting faulty or incomplete systems to the project site.

• Conducted at the manufacturer’s facility.

• Verifies hardware and software components meet functional specifications before delivery.

  2. IFAT (Integrated Factory Acceptance Test)

  Where multiple components or systems interact – such as in signaling, control, and communication – an Integrated FAT is often conducted. This phase ensures that interconnected components from different vendors work together as a unit. IFAT focuses on interface compatibility, data exchange, and logical operations between subsystems under controlled conditions at the factory.

  • Integrates multiple components (e.g., controller + software + hardware).

  • Ensures compatibility between interfacing systems at factory level.

3. Pre-SAT (Preliminary Site Acceptance Test)

Once the equipment is delivered and installed, a preliminary test phase (Pre-SAT) is carried out to verify basic installation correctness and readiness for full site testing. This includes initial powering-up of equipment, configuration verification, cable terminations, and basic communication checks. Pre-SAT ensures that the environment is safe and suitable for conducting detailed functional tests.

• Verifies readiness and basic functionality at the installation site.

• Often includes power-on checks, cabling verification, and initial configuration.

4. SAT (Site Acceptance Test)

The SAT phase is where comprehensive testing begins at the actual project site. This stage verifies that each system or component functions as expected within the physical, operational, and environmental conditions of the installed location. SAT validates system behavior, responsiveness, alarms, fail-safes, and interactions with adjacent equipment or infrastructure. All issues must be resolved before moving on to system integration.

• Confirms installed systems meet requirements at the project site.

• Includes detailed functional testing in live or simulated environments. 5. SIT (System Integration Test)

SIT brings together all subsystems – such as CBTC, rolling stock, PSDs, and communications – and evaluates their interactions and real-time behavior as a fully integrated system. It tests critical interfaces, data flows, and control logic that span multiple technologies and suppliers. SIT ensures that the whole metro ecosystem works harmoniously, including functional handshakes between train-borne and wayside systems.

• Validates the integration and communication between subsystems (e.g., CBTC – PSD – Rolling Stock, CCS and its different interfaces.).

• Checks real-time operations and interoperability across the network.

6. SIAT (System Integration and Acceptance Test)

SIAT is an extended version of SIT with a broader scope. It assesses the end-to-end performance of the integrated system under realistic operating conditions, incorporating operator actions, control room functions, passenger behavior, and degraded modes. SIAT is often required by regulatory bodies as proof of safety and readiness before commencing operational trials.

• Full end-to-end testing of all integrated systems under near-operational conditions.

• Ensures all systems collectively meet user, performance, and safety requirements.

7. Dynamic Train Testing:
Dynamic train testing in metro rail systems assesses train performance, safety, and infrastructure compatibility under operational conditions. It involves operating trains on tracks to evaluate mechanical, electrical, and infrastructure systems, ensuring compliance with global safety and performance standards (e.g., EN 14363, IEEE 1474). Dynamic testing is categorized into low- speed dynamic testing and high-speed dynamic testing, each targeting distinct operational aspects.

• Low Speed Train Dynamic Testing
Conducted at 20–40 km/h, low-speed dynamic testing focuses on infrastructure validation rather than active train or signalling system testing. Key activities include:

• Track Data Collection: Uses specialized trains equipped with sensors and lasers to measure track geometry (gauge, cant, alignment) for compliance with standards like UIC 518.

• Verification: Compares collected data against design specifications to ensure track integrity.

• Kinematic Envelope Testing: Evaluates the train’s dynamic movement boundaries (lateral/vertical oscillations) to confirm clearance from infrastructure, using 3D modeling or sensors per EN 15273-2. This differs from static gauge testing by accounting for motion- induced sway.

• High Speed Train Dynamic Testing
Performed at or near maximum operational speeds (80–100 km/h or higher), high-speed dynamic testing evaluates train and system performance. It includes:

• Train Systems: Tests traction, braking, and stability under operational stress.

• Signalling/CBTC: Actively validates CBTC functions, such as automatic train protection

  (ATP) and moving-block operations, ensuring precise train control.

• Track-Train Interaction: Assesses wheel-rail dynamics, vibration, and ride quality under

  full loads.

  Performance Testing Stages

  Once technical integration is proven, the system enters a series of performance-based tests designed to validate stability, reliability, and operational readiness over time.

1. SPT (System Performance Test)

SPT focuses on measuring how the system performs over extended durations, especially under simulated or live operational loads. It helps uncover intermittent faults, verify reliability targets, and ensure stable operations. This includes stress testing of the control systems, real-time monitoring, and verification of safety-related functions under repeated cycles.

• Assesses system stability and performance over time.

• Includes reliability checks, failure response, and degraded mode performance.

  2. CPT (Capacity Performance Test)

  CPT evaluates whether the entire system meets the completion criteria set out in project agreements or regulatory requirements. It typically includes trial runs under normal operating conditions, with operator and maintainer involvement. CPT verifies schedule adherence, response times, redundancy handling, and compliance with key performance indicators (KPIs).

• Verifies the system’s ability to operate according to the final design under full load and passenger conditions.

3. FPT (Final Performance Test)

FPT is the final phase before handover and commissioning into passenger service. It confirms that all previous issues have been resolved, all performance targets are met, and that the system is ready for revenue service. FPT often involves formal approval from client representatives, regulatory authorities, and safety assessors.

• Conducted just before handover.

• Demonstrates operational readiness, compliance with KPIs, and safety for revenue service.

These progressive T&C phases ensure that complex metro systems are tested thoroughly—from the first component switch-on to full-scale operational readiness—enabling a safe, efficient, and smooth transition to live passenger service.

T&C Phases by Subsystem
Here’s how the phases apply across key metro subsystems: