What are necessary procedures and actions taken when the sub-contractor is not capable to execute the works as per the contractual commitments?

The Project Management has guidelines and work program to watch the subcontractors performance at the project site. This control and watching system include whole works implemented during the execution phase of the project particularly the subcontractors performance / percentage of the commitment in the technical specifications and level of the implementation. Any delaying and no commitment in the agreed specifications. Project Management have to start some procedures against the subcontractor, Kindly explain and confirm some procedures required in a such case.