The research, which spans across the public and private sectors and gauges the views of the HR leaders of some of the UK's biggest organisations, revealed nearly two in five (37%) of senior HR professionals think the purpose and values of the HR function are poorly defined.
The research suggests the failure of some HR departments to define their purpose is the major reason why more than a quarter of the UK's HR departments are deemed ineffective.
It also found a lack of mechanisms to evaluate the performance of HR is another reason behind the ineffectiveness of some departments. More than half (54%) of senior HR professionals admit there are no mechanisms in place to evaluate the effectiveness of HR.
Jane Chesters, partner at Orion, said: "There are areas where HR departments are particularly strong. But those strengths are interspersed with two major weaknesses. First, is a lack of mechanisms to evaluate the effectiveness of HR.
"It means some departments are essentially flying blind. The second is a worrying failure to define the business purpose of the HR department and the set of values, which guide it.
Chesters added: "If business purpose and values aren't clearly defined, it is difficult for HR leaders to communicate their vision, and that stymies the ability of the department to implement an effective strategy."
The research found the failure to define the purpose of the function is compounded by a failure to articulate the commercial and business value that new HR initiatives have.
Almost a third (30%) of senior HR professionals think new initiatives are not communicated in a way, which explains their relevance to business objectives and commercial goals. And one in six (17%) of senior HR professionals say their department isn't close to the rest of the business.
Chesters added: "Great HR manifests itself at two levels: organisational and individual. When organisations get it right we see it in the way the function is structured, its systems, its processes and governance.
"At an individual level, it defines the mind-set and capabilities, which drive successful HR."
She added: "If HR struggles to define the purpose of their own department, and how that relates to the aims of the business, their influence at the top table is diminished."
The research polled 67 HR leaders and senior professionals at organisations with a combined total of 1.1 million UK employees.
