Washington ? The FBI’s failure to roll out an expanded computer system that would help agents investigate criminals and terrorists is the latest in a series of costly technology blunders by government over more than a decade.

Experts blame poor planning, rapid industry advances and the massive scope of some complex projects whose price tags can run into billions of dollars at U.S. agencies with tens of thousands of employees.

“There are very few success stories,” said Paul Brubaker, former deputy chief information officer at the Pentagon. “Failures are very common, and they’ve been common for a long time.”

The FBI said earlier this month it might shelve its custom-built, $170 million “Virtual Case File” project because it was inadequate and outdated. The system was intended to help agents, analysts and others around the world share information without using paper or time-consuming scanning of documents.

Officials said commercial software might accomplish some of what the FBI needs.

The bureau’s mess — the subject of an investigation by the Justice Department and an upcoming congressional hearing — was the latest black eye among ambitious technology upgrades by the government since the 1990s.

The Internal Revenue Service sought $388 million last year for its $1.7 billion “Business System Modernization” program, which congressional investigators said continued to be over budget and 15 months late. The plan will modernize the IRS systems for collecting taxes, auditing returns and helping taxpayers with questions.

The Federal Aviation Administration has doubled its cost estimates to $1.69 billion for its “Standard Terminal Automation Replacement System” since 1996, according to the Transportation Department’s inspector general. The new system would replace the outdated computers that control air traffic within five to 50 miles of airports.

While these are current examples, the problem has lingered for years.

“The government is just as inept in buying computers as it is in using them for accounting,” declared a 1994 report, called “Computer Chaos,” from a Senate Governmental Affairs subcommittee. “The system is indeed broken and it is time to fix it.”

Critics said the FBI’s case illustrated government’s propensity to build its software from scratch, which can dramatically increase a project’s complexity and cost.