Carol Bellringer said the province spent seven years and $182 million trying to modernize aging computer systems but failed to replace two thirds of the old system.
In an audit released Tuesday, Bellringer concluded the government's Integrated Case Management system did not adequately protect sensitive personal information.
"The ICM project did not fully replace legacy systems as initially planned," Bellringer said in a report. "At project completion, about one third of the legacy systems had been replaced. This means that a number of systems characterized as antiquated and expensive to maintain must continue to run."
The report makes eight recommendations, including regularly monitoring the system for inappropriate access and activity and preparing full accounting of its capital and operating costs.
At a news conference, Bellringer did not directly counter last November's government statement that the ICM project was completed on time and on budget, but said, "while it was, if you will, on time and on budget, that was with a reduced scope."
She said she only recently became aware the project was nominated for an award of excellence within B.C.'s civil service.
"I found it interesting," Bellringer said.
The ICM project dates back to 2008 and was meant to replace outdated computer systems used to deliver social programs including child protection, child-care subsidies and income assistance.
Last May, the system crashed regularly and frustrated staff but the government said it was still able to meet the needs of social services clients.
B.C.'s independent representative for children and youth has been raising concerns about the system for the past three years.
Mary Ellen Turpel-Lafond said vulnerable children and families could be at risk because information for social agencies and police is not being properly processed.
A report by Turpel-Lafond in July 2012 prompted the Children's Ministry to admit its computer program needed fixing.
Social Development Minister Michelle Stilwell said the ICM project is now providing services to 200,000 clients. She said seven of the audit's eight recommendations are already in place.
"We have met our key objective and successfully implemented a very modern technology platform," she said.
Stilwell said the ministry will continue to work towards replacing the remaining systems with the ICM model.
But B.C. Government and Services Union spokesman Doug Kinna said ICM is not making life easier for social service staff who work with ministry clients.
He said monthly client report cards that were previously completed in seven steps now take 21 steps to do the same work.
"This isn't a better tool," he said. "The (ICM) system is cumbersome and clunky."
Kinna said documents that took two or three days to process under the previous system now take between five and seven days.
NDP social development critic Michelle Mungall said the government's comments about the ICM system being on time and on budget are hardly fitting considering the auditor general called the multimillion-dollar system dysfunctional and unfinished.