After revelations the Department of Family and Community Services is failing to see a growing number of vulnerable children, a senior bureaucrat has also admitted caseworkers spend so much time bogged down in paperwork that they struggle to meet those at risk.

''Caseworker positions are being filled temporarily and they are being moved from office to office,'' Public Service Association assistant general secretary Steve Turner said.

''This doesn't allow for proper co-ordination and planning and it also creates low morale because workers don't feel secure in their jobs.''

On Tuesday the government's latest quarterly figures showed a reduction in child protection worker vacancies from 13 per cent to 11 per cent but there are still pockets around the state where they remain as high as 31 per cent. There are also a growing number of children not visited at home by the department.

''To have more than 10 per cent of your staff unfilled is a big slice of your budget,'' Mr Turner said. ''What other frontline service would risk running with 10 per cent vacancies?

''Workers are having to make horrific decisions about which children they will visit and which ones they won't visit.

''Vacancies need to be filled permanently to better manage notifications of children at risk. If the number of notifications is rising, there are questions about whether we have enough staff if all vacancies are filled.''

Family and Community Services secretary Michael Coutts-Trotter said that the latest snapshot on vacancy rate figures was ''an encouraging result but the current vacancy rate is still too high and we have to keep working to improve our recruitment".

One of the most senior bureaucrats in the Department of Family and Community Services has admitted time management is a key weakness in the department.

Kate Alexander, who is charged with improving child protection, told the Royal Commission into Institutional Responses to Child Sexual Abuse that that reports of child abuse have increased dramatically since the 1990s.

''All of that has led us to, at times, in recent years, becoming a bit too forensic in our approach, and that means perhaps more time spent at computers than we would like and less time spent directly in the field with families,'' she said.

She told the commission that staffing numbers were adequate but caseworkers needed to be freed up for visits with young people at risk.

''We are working very hard at the moment, through a whole host of reform strategies, to increase our ability to free our workforce up,'' she said.

However, Ms Alexander acknowledged that serious reports of abuse were still slipping through the cracks.