The WA Police Union fears officers may become increasingly stressed and fatigued under a new policing model to be rolled out across the metropolitan area that has been credited with driving down crime in some of Perth's worst trouble spots.
Officers have been split into response and local policing teams during a six-month trial in the busy south-east metropolitan district, which includes Armadale, Gosnells and Cannington.
Union president George Til- bury said though the model overall seemed "sound", it had been understaffed and officers overworked.
Mr Tilbury warned that if that continued there was likely to be an increase in fatigue and stress-related illnesses.
But Police Commissioner Karl O'Callaghan said fewer officers had taken sick leave since the changes were made in November.
He conceded yesterday that staff numbers in the district were about 50 short of the 550 target.
More officers were being recruited and he believed that bolstered staffing would alleviate many concerns.
Mr Tilbury wants immediate changes to raise officer numbers and adapt rosters before the model is rolled out to other districts.
He has highlighted problems raised with the union in a survey about the changes. About 55 per cent of officers in the trial district responded to the survey.
Mr Tilbury said most concerning was the adverse impact on officers in the response teams, with most claiming they did not have time during their shifts for their administrative tasks, their meal breaks were often interrupted and more than half felt the rosters were inflexible.
Those officers, who responded to calls for help, were under enormous pressure to handle the workload, he said. "A number of our members are being forced to complete paperwork in their own time with no overtime paid to them," Mr Tilbury said.
Mr O'Callaghan said he was not surprised by some of the survey findings and it had been quite useful to get feedback.
He said WA Police would look at the rostering system and claims that officers were missing meal breaks.
But he conceded rosters would not satisfy every officer, because his priority was to make sure there were enough police on duty to meet demand.