Inspectors looking at how South Yorkshire Police keeps people safe and reduces crime said the force 'requires improvement'.
Her Majesty's Inspectorate of Constabularies looked at the efficiency of the force and found it has a 'limited understanding of current and future demand and workforce capability', which inspectors said is 'adversely' affecting the quality of services it provides.
HMIC said a new operating model introduced in 2015, after the last inspection, had failed to work.
Inspectors found that although the force has 'resourced' its highest priorities it has not been able to provide 'resilient call handling' and 24-hour community policing.
They found the force struggling to answer non-emergency calls from the public and said demand on officers means that 'community engagement' and 'preventative policing' is 'diminishing'.
Inspectors found that some PCSOs working in communities had been deployed to incidents elsewhere to resolve issues they did not have the powers to deal with.
The report said: "The force’s response to calls from the public is poor. The risks are deemed to be so great that the force is currently managing its call handling services as a critical incident.
"In the period leading up to the inspection, the force reported that only 30 percent of non-emergency calls were answered within the target of 30 seconds and up to 21 per cent of calls were abandoned each day.
"Frontline officers are also waiting for extended periods of time for the staff in the crime management unit to answer their calls and record reports of crime."
The report said there are a number of 'causes of concern' but that the force is developing plans to address them.
The report said: "The absence of a comprehensive workforce plan and understanding of the force's current workforce capability and capacity in South Yorkshire Police is a cause of concern, which compromises the force’s ability to match resources to demand and align workforce costs with the force budget.
"South Yorkshire Police’s limited understanding of current and likely future demand is a cause of concern, because further analysis is needed by the force to develop a complete picture of demand including under-reporting of crime, inefficient working practices which generate unnecessary demand, and greater engagement with communities and partners to more fully understand issues which may inform early intervention, prevention and problem solving opportunities.
"The absence of a coherent set of future plans in South Yorkshire Police is a cause of concern, because the financial plans are not linked to the workforce plans and the force does not have a complete understanding of future demand or workforce requirements."
Deputy Chief Constable, Rachel Barber, said: "South Yorkshire Police welcomes the latest HMIC report, the findings of which are similar to the conclusions of the Peer Review conducted by the College of Policing earlier this year, and those already recognised by the force through its own internal review.
"As such, we are already acting on the areas highlighted as requiring improvement by HMIC, in line with the recommendations provided.
"We will continue to build on this with the help of our partners and the public of South Yorkshire, while also maintaining our focus on the areas identified as requiring improvement.
"I am pleased that the report acknowledges the work already undertaken to provide officers and staff with the appropriate technology to enable them to spend more time out in our neighbourhoods.
"We recognise that the model introduced in 2015 does not provide the most appropriate service to meet the changing needs of South Yorkshire's diverse communities and as such, work is ongoing to redesign our local policing.
"We are already working to better understand the demand for services and what this means for the public of South Yorkshire.
"To enable us to better address community issues across the county, work is ongoing with partner agencies and blue light services to develop joint working arrangements and I'm pleased to see this reflected in the report.
"It also recognises our track record in working with other police forces to improve efficiency, and while we recognise that South Yorkshire Police has some hurdles to overcome, I feel positive that the force is making good progress.
"Every officer and member of staff within South Yorkshire Police is committed to ensuring our communities can have trust and confidence in the force, and we will continue to listen to the public to ensure we are preventing and fighting crime and protecting communities."