Cummings' statements came during a City Council Public Safety Committee hearing looking into LAFD response times and other problems with the agency. The department has faced criticism over revelations that it misled the council on how often it meets the national standard of responding to calls within five minutes 90 percent of the time.
"To get to everyone in under five minutes, we would need to add 89 facilities to be that close to every resident in the city," Cummings told the committee.
Cummings was told to return to the committee with more detailed data on response times.
The meeting came at the conclusion of a week of controversy over the LAFD and its ability to respond to emergencies and budget cuts that have reduced its services over the past three years.
Earlier in the week, Mayor Antonio Villaraigosa announced he has hired an outside consultant, Jeff Godown, to serve as interim director of Statistical Analysis and Review. Godown had previously been in charge of the Los Angeles Police Department's CompStat bureau, which was responsible for geographic analysis of crime activity throughout the city.
The mayor also said he will provide funding to have six additional ambulances available throughout the city.
As part of their review, panel members said they want more detailed reports from Cummings and other city officials on the possibility of hiring a third party consultant to analyze the department's response time.
It also asked for a report on developing a FireStat program on where resources are deployed.
Former Chief Millage Peaks developed the current deployment plan, designed to eliminate the modified deployment plan in which 18 units were out of service at any given time.
Councilman Mitch Englander, who chairs the panel, said he recalls a neighborhood council meeting where Cummings said the new system was designed to provide more flexibility for change.
"We held off because any changes we made might have created anomalies in other parts of the city," Cummings said.
Cummings said the department responds to 60 percent of its calls within five minutes(5:59 minutes) and 90 percent within seven minutes, 18 seconds.
Factors that need to be considered are the time of day a call comes in, the geography units must drive through and the distance of a station from the calls, officials said.
Pat McOsker, president of United Firefighters of Los Angeles City, blamed the mayor and the City Council for three successive years of budget cuts resulting in the problems facing the department.
"This (deployment) program was sold to you on false pretenses," McOsker said. "We have had constantly changing stories. Every time they speak, the Fire Department has come up with a new story."
Cummings said the department has been compiling all information on exact response times around the city to make available to officials and any consultants hired.
City Controller Wendy Greuel has announced she also plans to review the department's response times.