A new integrated and unified management system has started across the six hospitals in the midwest.
Its aim is to bring greater efficiencies in the delivery of critical and medical care.
Four new clinical directorates will operate across the six hospitals in counties Limerick, Clare and Tipperary.
The six hospitals in the group are the Mid Western Regional Hospital in Limerick; the regional hospitals in Ennis and Nenagh; the orthopaedic hospital in Croom; the Mid Western Regional Maternity Hospital in Limerick and the voluntary St John's Hospital in Limerick.
Limerick's Mid Western Regional Hospital provides 24-hour acute care, as well as being one of the designated cancer care centres providing chemotherapy and radiotherapy services, and specialist cardiac services.
Under the new system, four directorate managers and four clinical doctor managers will take charge of the delivery of specialist services across all six hospitals, instead of being responsible for delivery of services in just one hospital.
The four areas are peri-operative care, medical care, diagnostics and maternal and child health.
A spokesperson for the HSE said the new system is designed to bring more efficient delivery of patient care in the region and address some of the deficits in specialist services.