Design flaws and poor management during the installation of the radio system for Honolulu police led to millions in cost overruns that nearly doubled the price tag to $64.8 million, a city audit shows.

The 800-megahertz telecommunications system is reliable, but as the 1990s-vintage system gets older, there are new challenges such as a lack of vendors for repairs and difficulty getting replacement parts, the audit said.

In a response to the audit, the Honolulu Police Department said it met in March with the manufacturer of the system, Harris Communications, to discuss upgrading the radio technology to a nonproprietary digital voice system.

The audit, ordered by the City Council in 2003 because of glitches, outages and voice problems, was completed last month.

When installation began in 1990, the city expected to receive a ready-to-use system that would be finished in three years by contractor Ericsson-General Electric Mobile Communications at a cost of $34 million.

Instead, installation took 11 years and cost $64.8 million.

The contractor was liable for daily penalties with a total cap of about $10 million for the project, but the city approved the time extensions and accepted the system, nullifying the fines, the audit said.

During implementation, project managers made 31 change orders and four contract amendments to correct design flaws and expand the scope of the system, the audit said.

Flaws in design caused insufficient signal amplification, the wrong equipment and obsolete technology, prolonging the installation process, the audit said.

During deployment, the Honolulu Police Department had to switch back to analog radios until radios with the latest technology could be purchased, and laptops had to be replaced by faster ones, the audit said.

While problems have been corrected and the Police Department has taken actions to prolong the system’s life, support for repair and maintenance might soon no longer exist. The current service vendor, Harris Corp., has warned that the city could invalidate its warranties by performing unauthorized repairs or service on the system.

The audit said a risk-management assessment is needed to create new security measures and decide whether to extend the life of the system or replace it. A backup plan in the event of a system failure is also needed.

The audit said any future system or project to upgrade it should have cost controls.