The HSE has said the number of people waiting in excess of four months for outpatient assessment and in-patient treatment, are unacceptably and unsustainably high.
The executive was responding to the European Health Consumer Index, published today, which ranked Ireland 21st out of 35 countries examined.
The index found waiting times here for emergency care are among the worst for the countries examined.
In its response to the European Health Consumer Index, the HSE said the executive acknowledged in its 2016 Service Plan that it lacks capacity to provide the type of accessible health services required to meet the current and emerging needs of the population of Ireland.
It said that the twin impact of the economic recession and demographic changes in recent years, has left the needs of the population and the capacity of the health system out of balance.
It also said it is working to ensure that no one is waiting more than 18 months for an outpatient appointment, or inpatient treatment.
The index scored Ireland poorly for access to services but high on access to medicines, including new drugs.
Ireland also scored badly in waiting times for minor operations and CT scans.
Ireland's rank of 21st place is up one on 2014, with Macedonia, Croatia and Slovenia ranked ahead.
The index says that Irish patient organisations have been radically more pessimistic in their responses to the survey conducted as part of the EHCI research.
It says the fact that Ireland has the highest percentage of the population buying duplicate healthcare insurance also presents a problem.
The report says that as the same pessimistic results occurred in 2015, Ireland, the UK and Sweden had the worst patient organisation feedback on accessibility among the 35 countries examined and this raises doubts about the validity of official statistics.
The report says that after several years of accepting official Irish waiting-time statistics, the index has scored Ireland on patients' versions of waiting times.
The index has been published by the private Swedish firm, Health Consumer Powerhouse since 2005 and covers 48 indicators across 35 countries, including patient rights, information and access to care.
The best performing health system is in The Netherlands, which scored 916 points out of a maximum of 1,000.
Netherlands leads the way
The report says The Netherlands dealt with one of its traditional weak spots of accessibility by setting up 160 primary care centres, which have opened surgeries 24 hours a day, seven days a week.
Given the small size of the country, this puts a clinic within easy reach for anybody.
It also has the best and most structured arrangement for patient organisation participation in healthcare decision and policy making in Europe.
The Netherlands has been consistently among the top three in ranking since the index was compiled.
The report says there should be a lot to learn from looking deeply into the Dutch process.
No country excels across all areas examined.
The worst performing country is Montenegro with 484 points.
The report says there is no correlation between accessibility to healthcare and money spent.
It says it is inherently cheaper to run a health system without waiting lists, than having waiting lists.
"Contrary to popular belief, not least among healthcare politicians, waiting lists do not save money.
Healthcare is basically a process industry. As any professional manager from such an industry would know, smooth procedures with a minimum of pause or interruption is key to keeping costs low", the report says.
Overall, the EHCI says that European healthcare is steadily improving, in spite of the problems caused by the financial crisis and austerity measures, the ageing population and migration turmoil.
Survival rates are increasing for heart disease, stroke and cancer, with infant mortality decreasing.
Responding to the index today the HSE also said it accepts that it has challenges in relation to data, primarily due to the lack of investment during the recession, the Irish health system has been late introducing technology which has inhibited its ability to properly track an individual's interaction with the health service.
It said new initiatives will allow the collection of more reliable data on a patient's journey through the Irish health system, which in turn can factually inform reports such as the EHCI.
Health minister responds to index findings
Commenting on the findings, Minister for Health Leo Varadkar said he "wouldn't put too much store in" the European Health Consumer Index which he said was carried out by a private company in Sweden and had nothing to do with the EU, the OECD, or the WHO.
The minister said it did show very long waiting times to see a doctor in emergency departments, and while he said this was not something that we actually counted here he said he had no doubt that Ireland did not compare well with other countries in this regard.
The minister said that this was something that was being addressed by increasing the number of consultants and doctors working in emergency departments.
However, he also noted that Ireland had gone up 30 points on last year and had moved up one point in the index's ranking.