Critical Days involve situations where the operating conditions may threaten the integrity of the pipe. Normally a gas pipeline's tariff provides Gas Control with the ability to take necessary actions to ensure the safety of the pipeline and provide firm entitlements to its customers. The tariff normally defines applicable situations for critical days.

The ePipeMaster critical day process is important because it helps schedule gas based on operational conditions, ensuring the pipeline is fully utilized in accordance with customers’ priority of service.

ePipeMaster implemented several general critical day module which can be picked by each business unit. Meanwhile, ePipeMaster's flexible structure gives our customer the flexibility to implement their own critical day module. ePipeMaster's critical day modules fully integrated with the scheduling module to guarantee the pipeline is operated based on operational conditions and ensure the pipeline is fully utilized in accordance with customers’ priority of service